A Yorkshire (West Riding) Lexicon:

All is Gaelic in Origin

  Steve Moxon, May 3, 2021. stevemoxon3(at)talktalk.net

Here is a first draft of a lexicon with full derivations of the words particularly familiar to people of Pennine Yorkshire — the hilly south-west that formerly was the West Riding; more specifically the western edge of Yorkshire that is part of the Dark Peak — roughly showing that all are of Gaelic, not Norse or Anglo-Saxon (Germanic), in etymology. This is in keeping with parallel findings (here on other pages of this website) re the continuity items forming the core of local vernacular conversation, place-names, and, most recently, sayings — these last being especially revealing, as whole-phrase Anglicisation-cum-rationalisation from Gaelic into English is incontrovertible.

This is by no means an exhaustive or comprehensive list, but it is lengthy enough to prove the point, albeit excluding sayings, words for land divisions (riding, wapentake, bierlaw, -thwaite, -thorpe, etc, all also turn out to be from Gaelic) and also the common conversational glue of our local vernacular speech (these each are in their separate sections). Nor are included less well-known or more specialised (as for agriculture) terms. Conversely, many of these words are familar or not unfamiliar across Britain, being included here because they seem to have particular resonance locally.

Without exception, every word investigated proved to have a (Scottish) Gaelic root, that easily out-competed derivation in terms of Norse and also Old English.

Many items less familiar or unknown beyond West Yorkshire likely once were current throughout England or Britain but have become more confined to Yorkshire. It is becoming evident that English itself grew out of Gaelic, or Proto-Celtic.  Recent fine-scale genetic research shows that even Anglo-Saxon as well as Norse peoples constituted very small incursions, which cannot possibly have produced language replacement. It is now thought that a Proto-English emerged in the east of Britain thousands of years earlier than hitherto supposed, in which case it arose among migrants who came here from northern Europe at a time when Proto-Celtic was likely their language.

A Gaelic basis of English was long ago proposed (in 1877) by Charles Mackay, though his derivations were frequently if not mostly awry — better alternative Gaelic roots than his choices are availablet. Together with the very restricted set of English words he chose to work on, Mackay didn’t make a very convincing case, but he appears nonetheless to have been right in his overall conclusion.   

Aeriated very agitated about something
earaileach, ‘exhorting, giving caution, warning; importunate, urging’.
After seeking, as in “I’m afer mi dinner”
às deidh, ‘after’, in the sense of ‘acquiring’; from asada, asad, ‘from thee’.
Allus usual, custom, or habit, rather than always per se
oileas, ‘custom, use, habit, usage’. A number of related meanings have been rolled into one and mistaken as English always rendered lazily.     
Arrus our house
aros, “ár’-us”, ‘house’.
Arse the rear end, bum
air-ais, “ar-aish” ‘to the back, backwards’.
Back End Autumn At Back O’T Door stupid
bacaidh, ‘shall or will hinder’; bliadhna dhorcha pronounced “blee-en-a”. ‘autumn’. Recorded as Scots backen but it’s northern Britain generally, from numerous very similar Scottish Gaelic words with the stem bac, ‘a hindrance, interruption, impediment, delay’, specifically rooted in Old Irish baccaid, ‘hinders, prevents, impairs; lames’. This is apposite, as autumn is a delay to the sun and the growing and mating season.
Back Room kitchen
biadh-chluan, ‘kitchen’, from biadh, ‘food’ and a word related to cluais, ‘handle of a dish’.
Badly ill
bá tinn, ‘sick’, from  tinn, ‘ill, bad’ and , ‘sympathy, feel, care’.
Bags / Bagsy to claim something for yourself
bag, ‘big belly’, bagair(e), ‘a glutton’; bagair as a verb, ‘to threaten’; bagaid, bagailt, ‘a cluster, a bunch’.
Baht without
beud, “ba’d”, ‘loss, pity, harm, injury; a defect or blemish’. It is not the supposed OE root, be-utan, which means not ‘without’ but ‘be/by outside’ (and is what evolved to but, not bh’at), and anyway is itself likely derivative of the Gaelic. Utan means ‘from outside’ or ‘on the outside’, whereas the meaning of ba’ht is ‘without’ in the sense of ‘loss’. The word (likely with the same Gaelic root) is also in Norse, but there is no record of a prosthetic be-.
Bairn child
bearn, beair’n, beirn, ‘a breach; a gap, an aperture; a separation’: the very act of giving birth. ‘Bearing a child’ is the act of opening up to yield it. This is the root, not OE bearn, ‘descendant’, which is a derived meaning, indicating that word is also derivative of the Gaelic. So the understanding that this word is Scottish (lowland Scots) without being Gaelic is false.
Ban going, as in “I’m ban ‘om”
a bhàn, ‘down, downwards’, not, as claimed, from ‘Swedish’ afani. It’s by eclipsis from a(n) bh-fàn, ‘into a declivity’”, from fàn, ‘a declivity’.
Barney quarrel
barnaig, ‘summon, warn; give summons of removal’.
Beck stream or brook
baic, ‘a turn or twist’; baiceach, ‘having twists or turns’. The description seemingly came to be the label, surely reinforced by beag, “bek”, ‘little’, the other key feature of a stream. This constructive etymology suggests a Proto-Celtic basis of a separate evolution of Norse bekkr, with no need to assume this had influence in Britain.
Belt hit
buailte, from buail, ‘struck, beaten, thrashed’.
Belting / Pelting (Down) heavy fall of snow or rain
In Addy’s Sheffield Glossary, beltings are the shearings from sheep, a conjugation of Gaelic bearr, ‘to shear’, with subsequent Anglicisation / rationalisation. Heavy snowfall is taken as analagous to the cascade of white fluffy wool in sheep-shearing.
Berk idiot
bùiriche, ‘one who digs or delves; a mattock, hoe, little spade dibble’. 
Best (Room)
beosach, ‘bright, glittering; brisk; trim, spruce; dapper’; beosaich, ‘beautify, adorn, make spruce or tidy’.
Bint girl Buint Over pregnant
buinnteach, ‘one who is habitually loose in the bowels’. From buinne, ‘stream, torrent’. The allusion is to menstruation. It’s not the Arabic for ‘daughter’, as absurdly suggested, on the basis that it was first recorded circa 1850 from soldiers. But this is just the sort of time and circumstance that vernacular speech is earliest recorded, not that soldiers acquired a word from where they were serving.
Bit as in “in a bit”, a short period of time
biteag or bideag, ‘a morsell’, but specifically of time, from bith, ‘life, existence, being; living; the world’; bithre, ‘lifetime’.
Black Bright very dirty
balach na h-aimhreite, ‘a name given to a quarrelsome disorderly fellow’. From balach, ‘a lad, a young man, a clown, a fellow, a sturdy fellow’.
Blackleg someone who won’t join in a strike
bualadh nan laoch, ‘the battle of heroes’. Both those who insist on solidarity and the rebel who goes it alone are heroes in their different ways. The claims that it refers to strike-breakers arriving in the dark or that a black leg from working with coal is revealed upon rolling up trousers are the usual rationalisations turning out to be red herrings.
Bleeder / Blighter a general derogation
bleideire, ‘a pilferer; a beggar; a teasing petitioner; an impertinent fellow’; bleid, ‘larceny; cajoling, wheedling; solicitation, impertinence, envy, spite; bleideil, ‘impertinent, teasing, trouble-some; pilfering, thievish; invidious, spiteful’.
Bloody (an intensifier)
bloidhdeag, ‘a fragment, a splinter’ bloidhdean, n. pi. of bloidh, ‘fragments, splinters’.bloidhdear, ‘a battery; a place from which an attack is made’.
Blummin’ / Bloomin’ (an intensifier)
blomas, ‘ostentation’; blomasach, ‘ostentatious’.
Blue-arsed fly frenzied activity, as in “like a blue-arsed fly”
blaghmhanach, ‘a blustering fellow’; blaghaireachd, ‘blustering; boasting; bravado’; blaghantach, ‘boastful; blustering’. The bluebottle fly zips about in apparent great agitation, making for a good piece of folk etymology if mere rationalisation.
Bog toilet [Not bog, ‘marsh’, which also is Gaelic]
boige, ‘more or most effeminate’, relating to buinntech, ‘loose in the bowels’. A conflation in meaning here of bowel movements and menstruation.
Bogeyed half asleep, and bog-standard usual
boilsgean, ‘the middle, midst’.
Brass impudence
bras, ‘impudent’.
Bray to hit someone, as in “I’ll bray yer!”
braigh, “brae-yh”, ‘a loud report; a loud crack or clap; a heavy stroke’.
Brew a cup of tea
bruich, “bruech”, ‘simmered, boiled; simmer, boil’; ‘the state of being boiled or act of boiling’.
Brussen stubborn
briosaid, ‘belt, girdle’. The sense here is of tightening (firming up against alternatives).
Brush as in “daft as a brush”
broisg, “broeshg”, ‘excite, incite, stir up, provoke’; bras, ‘rash, impetuous’; brosguil, ‘flattery; lively talk’.
Buck Up Cheer up
buaiceach, “buaechg’-ach”, ‘giddy, light-headed, thoughtless; of, or belonging to, a wick’; from buaic, buaichd, ‘the wick of a candle, lamp, or torch’.
Busk scrub (an area of bushes)
biosgair, ‘a scrub’.
Button nose
Bòsd
Butty sandwich
biodailt, ‘food; victuals’.
By as in “by ‘eck”
bidh, “be”, from bithidh, ‘shall or will be’.
Cack crap Cack-Handed left-handed
cac, ‘excrement, faeces’. Cack-handed is used generally to denote a clumsy or wrong-headed approach to a task.
Cadge acquiring something in a not altogether above-board manner, if not being tantamount to theft
cadhag, “ca’-ag”, ‘jackdaw’. This bird species is famed for thievery.
Cake ‘oil mouth
cagain, “cag-enn”, ‘chew, gnaw, champ’. So cake ole means ‘chewing hole’.
Capped / Capt stumped
ceap-tuislidh, ‘a stumbling-block’.
Carr bog
càrr, càirr, ‘a bog, a fen or morass; moss’. This is not Old Norse kjarr, which actually means ‘brushwood’ within the compound word kjarr-mýrr, ‘marsh overgrown with brushwood’. So it’s mýrr that is the operative word meaning ‘bog’, NOT kjarr; and anyway this is from Scottish Gaelic mirr, that itself is clearly not a loanword into Gaelic given the closely related set of words with tangential meanings.
Casey a football
casach, ‘footed, many-footed; of, or belonging to, feet’.
Causey pavement, paved highway, path, track
coisich, ‘to move on the feet’.
Chamber
seòmar, seumar. Rather than a Gaelicisation of English, it seems to be the other way round, being old, from Irish seomra, and there is a cluster of words all from seomalta, ‘large, bulky’, with compound words for every kind of room. There is also the seemingly related seimleir, ‘a chimney; a vent’; and seulta, ‘sealed’. Even so, a suggested Latin word root could be the ultimate meaning, ‘arched over’.
Chelpin talking
chéile, “chyall-a”, ‘tête-à-tête; together, both together’. A conjugation or construction from this; possibly from the saying “ar scáth a chéile a mhaireann na daoine”, meaning ‘it’s in the shelter of each other’s shadows that we live’.
Chum good acquaintance or friend
chun, ‘to, towards’. The assumption has been that the origin is friends sharing chambers at university: a truly ridiculous, elitist stab at derivation, in the usual context of ‘etymology uncertain’.
Clagged-in foggy, low-cloud
clagharra, ‘sluggish’.
Clammy warm but moist or wet (as in a fever)
clumhar, ‘warm, sheltered, snug’. This is a stronger Anglicisation than the other take on this word as clover, (from mh pronounced “v”) as in being in clover.
Clarty dirty, muddy or sticky, especially regarding weather Clarht-eead silly, funny
clàiteachd, ‘gentle rain’, clàtar, ‘mire’.
(Stood Like) Clem doing nothing and looking gormless
cluain, “kluaen”, ‘pacification, quietness’; and/or cliob, “klebb”, an excrescence (a distinct outgrowth on a body, resulting from disease or abnormality); and/or cùl-cheim, ‘a back-step’.
Clem starved
cliabh, “kleav”, ‘thorax, chest, basket, pannier’: all are containers, which in themselves are empty. The thorax is the upper body containing the stomach and the rest of the upper part of the digestive system, where, if they are empty, pangs of hunger are felt. So the sense is of an empty body.. This fits with the meaning elsewhere in Britain to extend the notion of bodily emptiness beyond that of food to water (thirst) and heat (cold). Anglicisation-cum-rationalisation would reject a final “v” (Gaelic bh) if lenition (softening) hadn’t already denuded it sufficient to be confusable with other consonants. The usual suggested etymology is clutching at straws: a German word meaning ‘to jam, clamp, be stuck, or adhere (to a surface)’ does not relate in meaning even tangentially.
Clever
gle mhaith (Gaelic mh is “v”), ‘very good’.
Clobber clothes
cliabhach, “kleav-ach”, ‘chested; having a large chest; of, or belonging to the chest; like a basket’, cliabhan, ‘a small basket; a cage, cliabhrach, ‘the side or trunk of the body’.
Cod a foreman/supervisor of an area in the work place
co’dhiol, ‘compensate’. The cod in a Sheffield Steelworks was the chief worker given money by management to then distribute as pay packets among his crew as he saw fit.
Codding kidding — leading along in jokey deception
codach, “kod’d’-ach”, ‘invention; friendship’.
Cop to sustain something unwanted or unpleasant
ciap, ‘vex, torment’.
Courtin’ courtship (steady dating)
coit-cheann, “koejt-chyann”, ‘common, public, general’; cúirtéir, Irish ‘courter, wooer’; cúirtéireacht, ‘(act of) courting, wooing’. The meaning is publicly acknowledged wooing.
Crackin’ to get together to perform a task, as in “get crackin’”
craic, ‘fellowship’.
Daft ‘Aporth silly person, (taken to be) short for “daft halfpenny-worth”
deagh-mhaiseachadh, ‘an adorning, a decorating; an ornament’. Rationalised to mean ‘silly half-penny’; that is, next-to-valueless; this reflects the meaning of the original phrase: that the person is merely ornamental with no use. There is a saying taking this further: “tha neither use nor ornament!”
Dale valley
dail, ‘field / meadow / plain’, ‘valley’, a meaning by extension from ‘Celtic primitive’ dal, ’a share, portion’, which in turn gives rise to the attendant dàil, ‘a meeting, decree, neighbourhood, separate tribe’. So ultimately (originally) it’s a term denoting a tribal area of land. The deep antiquity in ‘Celtic’ shows it’s not from Norse, as unjustifiably usually assumed.
Darlin’ (Mi) actually a general term of endearment, not to a partner per se
m’eudail, ‘my darling, my dear’.
Delve to dig
dealbh, “dyal-uv”, ‘frame, form, make, contrive, devise, invent; feign; delineate’.
Dicky
duaichnidh, ‘deformed, ugly, dismal, black’.
Diddled cheated
diblidh, “dyeb’-lle”, ‘mean, abject, destitute; wretched, poor’; deadhail, ‘the separation of night and day ; the dawn of day’.
Didlin as in “how’re yer didlin’?”
didil, ‘great love, kindness’; deidheil (deidh-amhuil), ‘fond; amorous; desirous; addicted to’, from deidh, ‘desire, longing; fondness, love’ and amhuil, ‘like, resembling’.
Din
dian ‘vehement, violent’.
Dinner lunch
dinnear, which is shortened darna + biadh, ‘second’ + ‘meal’; daonnachd, ‘hospitality’ (many related words).
Do as in ‘a do’
, ‘meet, proper’, Early Irish . With related words such as dùthaich, dual, it’s clearly not a borrowed word, so is not, as supposed, from Old French  ( debntus), whence (supposedly) English due.
Doersen ‘door-step’
ursainn, ‘a door-post’.
Dog Shelf floor
do-ghluasad, ‘immovable; not easily moved’.
Dollop a lump of something, usually food
diolamdioghloim, “dyul’-em”, ‘gleanings’ (leftovers from crops); diolab, ‘legacy’; diol, ‘an object, end ; use; a selling; sufficiency’; diabladh, ‘twice as much, double’. An old word for a lump, portion, or share.
Dolly (Tub) wash tub
dioladh, ‘a restoring’, from diol, ‘restore’. This is a perfect fit in meaning for what washing clothes is about. A dolly (tub) was ubiquitous before washing machines: latterly barrel-shaped, of ribbed galvanised iron.
Don to put on (clothes)
dion, ‘shelter, protect, guard, cover’. A large word family including dion-bhreid, ‘an apron’.
Done worn out
dùin, “duen”, ‘shut, close’.
Down as in, eg, “I’m off down’t road” 
dàn, “dàn”, dana, ‘bold, daring, intrepid, resolute; forward, impudent, confident’; dion, ‘shelter, protection, defence, refuge’; daonnachd, ‘hospitality; liberality; humanity, civility’. There may be co-roots. The sense is not of ‘going’, which is indicated by ‘off’, and instead is a quality of the destination: that it is familiar and a place of safety.
Duck’s Back as in “water off a duck’s back”
duaireachadh, ‘slander’.
Eck hell, as in “blooming ‘eck!”
eag, eig, ‘death’. More properly aog or eug.
Eee By Gum trust me, falsely presumed to mean ‘oh my god’
earbaidh a gum, ‘I trust’, or, rather, ‘trust in me’; earbaidh a dia, ‘trust ye in God’; from earb, ‘trust, rely, confide’. Contrary to some rumour, this expression is not a caricature but actually used! At least until recently.
Eh what, or pardon, or an expression of confusion
earb, “erb”, ‘trust, rely, confide; tell, relate’.
Fair TMiddlin’ worthy though insufficient, or from worthy to insufficient’
fiù, “fu”, ‘worthy, fitting, value, desert’, and mi-dhiongaltahd, ‘insufficientness’; mi-dhiongalta, ‘insufficient’. The surface meaning of ‘fair to middling’ makes no sense, as middle and fair effectively are synonymous. A meaning of either ‘worthy though insufficient’ or ‘from worthy to insufficient’ expresses a meaningful distinction.
Faasht starved
fàs, ‘empty, void, hollow, waste, desolate, vacant’; fàsbhuainiche, ‘a starveling’.
Faffin’ messing about, as in “stop faffin about”
fiafrach, ‘inquisitive’, fiafraich, ‘inquire, ask’.
Famished
feumach, (from feum), ‘needful, needy, necessitous, in want’. The supposition it’s from Latin fames, ‘hunger’, is just that; but even if this were the case it may well be via Gaelic;most likely it’s a case of parallel evolution from a Proto-Indo-European origin.
Fancy know
faineacadh, ‘a recognising, a knowing, a feeling, perception’; faineachas, ‘perception’.
Fanny (about)
faoineachd, ‘vanity; silliness; idleness; emptiness, vacuity; toying, trifling’; faoineadh, ‘an indulging or humouring; indulgence’; faoineas, ‘vanity; idleness; silliness; vacuity, emptiness; toying, trifling’.
Far-fetched improbable, not pertinent, only remotely connected (if that)
forfeached, ‘perfection, perfecting’.
Fathom understand, work out
faotainn, “faont’-enn”, ‘a getting or obtaining; a finding; a receiving’; fathunn, fathuinn, or fathur, ‘report, news, rumour’; faothaid or faoghaid, ‘a chase, a hunt; starting a game’.
Fauce / Fawce unwittingly revealing, pawky, sly 
fiusach, ‘earnest’, fios, “fes”, ‘understanding’; foi-ghliocais, ‘low cunning; great prudence’; foillseachadh, ‘the act of revealing, showing, or manifesting; a revealment, discovery, manifestation, declaration, revelation’ (and many related, similar words); follais, ‘clear, conspicuous, evident’ (plus other related, similar words); fuas, ‘spectre, surprise, dread’. It’s often said, endearingly, of children as they begin to grow up and exhibit adult manner but with their still infant ways shining through.
Fettle to make, tidy or mend 
feathail, “fe’-al”, ‘quiet, calm, fixed’; feartail, ‘valorous; having virtue; miraculous; wonder-working’; feartas, ‘manly conduct, behaviour which becomes a man’. The claim it’s from an OE word meaning ‘to fetch’ or a Norse word meaning ‘strap’ makes no sense.
Fib(bin) lie, lying
feabhsach,’cunning, skilful’. fuabart, ‘spoiling’.
Fill Thi Booits enjoy yourself
fialmhor, ‘bountiful’, falaidheachd, ‘generosity, liberality, bountifulness’. Various grammatical variants from fial, ‘generous, liberal, bountiful’. Boots as vessels could be filled with whatever may be thought worth acquiring, and of course they are filled with your own good self.
Finicky too particular
finnidheach, ‘vigilant, prudent, cautious’; finealtachd, ‘fineness; fondness for dress; elegance; bravery’. fineachais, ‘kindred; inheritance; a nation; law. fineadach, ‘wise, prudent, sagacious, cunning; also, clannish; substantively, a clansman. fineadail, ‘national, clannish’. fineadalachd, ‘nationality, clannishness’.
Flabbergasted
foilearbadh, ‘death’; foillseachadh (Old Irish foillsiughadh) ‘the act of revealing, showing, or manifesting; a revealment, discovery, manifestation; declaration; revelation’. Of this word family — the precise derivation is elusive. Perhaps a severe mangling of foillsichidh do mhiorbhuilean, ‘thy wonders will declare’.
Flaggin’ getting tired
fleogain, ‘an untidy or flabby person; fleoganach, ‘untidy, tawdry’; falamh, ‘empty, void, vacant, wanting substance’.
Flippin’ Eck a term of shock or surprise
foilearbadh, ‘death’.
Flit to move house
foilleachd, ‘a track, a footstep; a tracing’; foill, ‘a pursuit, a chase’; foil, ‘a hiding-place’; foill, ‘deceit, fraud, trickery, treachery’. This word, like laik, is taken to be quintessential Norse, but here we can see the composite origin in meanings in Gaelic, indicating Gaelic etymology, leaving the Norse likely an independent evolution from Proto-Celtic origin, rather than the Norse word being a loan into English.
Flustered
fualiosgach, ‘causing strangury’; fualiosg, ‘a strangury’. A strangury is a condition caused by blockage or irritation at the base of the bladder, resulting in severe pain and a strong desire to urinate! feileasach, ‘frivolous; vain’.
Flummoxed confused
falamhachd, “fal’-uv-achg”, ‘emptiness, voidness, vacancy; avoid’; falamhaich, ‘empty; make void’.
Foot: Six/Eight/Ten … Foot all denoting an entry-way, alley
frith, “fre”, ‘mouth’, usually of a river but here referring to shràid, ‘street’; so here an alley is named in terms of a mouth into the street. Anglicisation-cum-rationalisation of frith produces foot. Alleys are then denoted in feet according to how  long, wide or tall they may be considered, though this is more symbolic than reality, of course.
Frame Thissen sort yourself out, try harder
faireach, “faer’-ach”, faireachadh, “faer’-ach-a”, ‘an awakening, a rousing from sleep’. Frame is a forced fit of the only English word that could fit meaning-wise while not straying too far sound-wise.
Friggin’ a curse, alternative to flaming, bloody, etc
frioghanach, “freú-gh’-an-ach”, ‘bristly, bristling, rough’.
Fuarrh! extremely cold
fuar, “fuar”, cold.
Gaffer a foreman (rather than a boss per se)
giofach, ‘dutiful; officious; attentive’; geimhean, ‘restraint, bondage’. [Gaelic mh is “v”, which typically softens to “f”.]
Gale very strong wind (a word common across Britain, but very favoured locally)
gailleann, “ga’lly’-unn”, ‘a storm or tempest’, rooted in gail, ‘boil, seethe, smoke, fume, vapour’. With the wide range in meaning of closely related words, then the etymology appears Gaelic with the usually supposed Norse being derivative.
Gallivant to roam about in search of pleasure or amusement; to play around amorously; flirt galabhas, ‘a parasite, a glutton, a flatterer’.
Gammy / Game as in “‘gammy leg” and “what’s your game?”
cam, ‘crooked, bent, distorted’.
Gander look
gan (for ag an) gan ruagadh, ‘pursuing them’. ganndar, ‘scarce, rare’. The sense is of searching for what is rare. This fits with the usage: ‘having a gander’ is in response to not finding something on initial perusal, and the former use in the 17th century to mean ‘to wander foolishly/aimlessly’.
Gennel, Ginnell, Jinty entry, alleyway
géinneil (geinn-amhuil), ‘cuneiform’ (wedge-shaped); geinn, ‘wedge; pin; squeeze, press’.
Get-up an effortful but incongruous dressing-up
giobal, “geb’-all”,‘a rag, cast clothes, a garment’.
Gibberish
gabaireachd, ‘garrulity; the habit of prating or tattling’.
Giorr give over (stop it)
giorra, “guerr’-a”, ‘shorter; shortest, abridged’. Taken to be simply a lazy way of saying ‘stop it’, it may actually be a word with similar meaning from Gaelic: not to fully stop but ‘wind yer neck in’, as it were.
Goff / Guff fart, horrible smell
goimh, goev”, ‘a pang, a throb, anguish, agonising pain; a grudge; vexation; a storm’; giomh, ‘a defect, fault’.
Good Nick in fine condition
cumhnantaich, “kuv-nant-ech”, ‘condition’.
Gormless lacking either sense or initiative
gorgachas, ‘foolishness, pervishness, dotage’.
Gummins the essential inner workings of something [This is the usage locally where I grew up, yet I can find no recording of it]
c’uime, (cia uime), ‘wherefore? why? concerning what?’ [A grammatical modification of this] ag obair, ‘workings’ is pronounced peculiarly with a terminal “s” sound, that with a usual softening (lenition) of the b would produce the Anglicisation gummins. cummins,in the ‘Urban Dictionary’ (USA) is “the biggest and most bad ass source of power known to mankind”.
Gumption
gun cheill, ‘witless’.
Gyp cheat
goid, “guejj”, ‘steal, pilfer, sneak, slip’; not from gypsy.
Hoik lift up
uchdach, ‘height’: Gaelic uch, ug and uig all denote ‘height’, so a variety of inter-related forms, any of which are liable to be aspirated — to take a prosthetic h — to Anglicise to hoik.
House the main living room (not the posh front room)
aos, ‘a set of people’.
Huff as in “in a huff”
uabhar, ‘pride, insolence vain-glory’; uabharach, ‘ill-tempered, proud’.
Jammy lucky
guamach, “guam’-ach”, ‘smirking; neat, tidy, well-formed; pleasant; careful’. This captures the essence, which rather than luck is the implied smugness at having the luck — as in “you jammy bastard”. 
Jaunt a short excursion for pleasure
diàn, “jeàn”, ‘hasty, quick, impetuous’.
Jazzy notability of attire, not derogatory (at least not originally)
deise, “jazey”, ‘a suit of clothes’; deisead, ‘elegance’; deiseachd, ’handsomeness or elegance of attire’.
Jerry badly constructed, as in “jerry-built”
deireas, “jeireas”, injury, harm, detriment; a fraud, a cheat; deireasach, mischievous, detrimental’.
Jiggered tired, exhausted
sgìthichte, ‘tired, wearied, fatigued’.
Job any sort of successful activity, as in “t’job’s a good ‘un”
dhearbh, ‘proved; affirmed’. [Initial dh is the nearest sound in Gaelic to “j”]
Jumble a mass of various items, some still of use, some not
diombuil, “dyèmb’-bùl”, waste, profusion; diombuilich, to waste, to dissipate, to put to bad use.
Kaylied extremely drunk
càail, ‘disposition, quality, life, strength’; caileas, ‘lethargy’; cailleadh, ‘castration’.
Keks pants or trousers
ceigeag, ‘a turd; (in contempt) a diminutive person; ceigeanach, ‘like a turd, squat, a diminutive person’.
Kerfuffle a fussy mess
car-fhoclach, ‘quibbling, prevaricating’, perhaps relating to cabhag, ‘confusion’, (and Irish cíor thuathail, ‘confusion, bewilderment’); cuir air falbh, ‘discharge, send off’.
Ketty rancid, as for ‘off’ meat, offal or rubbish
ceathach, vapour’, ceath, ‘skim’ (presumably denoting a coating of bacterial growth), ciontach, ‘faulty’.
Kiddin’ / Coddin’ joking
codach, ‘invention; friendship’; guidh, v ‘beseech, implore; pray; imprecate’.ghuidh, ‘prayed’. guidhe, ‘a prayer, an imprecation; intercession’. guidheach, a. ‘prone to beseech; imploring. guidheachair, ‘a supplicant; a petitioner; a swearer. guidheachan, ‘an earnest prayer; a petition; an imprecation’. guidheadh, ‘a beseeching; an imprecating; an obsecration’.
Lackadaisical carelessly lazy
lag-chridheachd, ‘faint-heartedness; cowardliness; dejectedness’. A very large number of inter-related words with a great variety of spellings and grammatical constructions, eg, leoganach, ‘slovenly, untidy, tawdry’.
Laddie / Lad a boy, man: a male human of any age
làidir, “lajj’-er”, ‘strong, powerful, able-bodied’, by contrast with the female.
Laik / laiking freedom in action
leig as, ‘set free, let go, loosen’, in the sense of permitting, as signified by the added preposition. The meaning is ‘to be allowed to be free’, rather than playing per se. Related is ligeach, ‘sly, cunning’. The usual derivation of a Norse word meaning simply ‘play’ doesn’t fit the meaning, and with a cluster of inter-related words in Gaelic, it’s clearly not a loan word from Norse. The loaning appears to be the other way round.
Lamp to strike or hit
lamh, “làv”, ‘a hand; an arm’; làmhach, ‘ready-handed; daring’; lamhach, ‘shooting, slinging, casting, the report of guns’.
Larrup a good beating
leireadh, “lyarr-a”, ‘paining, wounding, hurting’, and leor, enough, sufficiency’.
Lash paying for something, perhaps extravagantly, as in “lashing out on …”
lach, “llach”, lacha, ‘a reckoning at an inn, the expense of a wedding or public entertainment’.
Lassie / Lass a girl, woman: a human female of any age 
sliasach, ‘having large thighs’; leis, “lyash”, ‘of thigh’; leas, “lless” ‘ thigh’. For human females, hormones at puberty cause pronounced fat deposition in the thighs to considerably enlarge them. By contrast, males put on muscle mass, and in places other than the thighs. So here is a major basis of distinguishing between the sexes. There may be a secondary root in lasach, ‘loose, loosened, slack; not firm’ (describing in general the profound subcutaneous fat layer in the female, in contrast to the corresponding word denoting the opposite sex, làidir, ‘strong, powerful, able-bodied’, pointing up the general very large increase in muscle tissue in the male).
Lathered hot, as in “in a lather”
làth bruich, ‘sultry day’. A rationalisation betrayed as such in not making sense: idiomatic in a lather, ‘in an agitated state’, is not the effect of hot weather — lather is foam arising in washing; hardly sweat.
Leather to beat or thrash
leidir, ’to thrash or drub lustily’, leadair, ‘mangle, thrust, thrash, beat round’.
Legged (It) dropping something and running away Liggin’ laying around in a lazy, gormless fashion
leigeidh, “llyeg’-i“, ‘a letting down; a throwing down, lay’. Many words, grammatical constructions and phrases from a stem of leig, ‘let fall, overturn, lower, diminish. lay’.
Let-on to reveal a secret
leth-aon, ‘a match, a fellow, one of a pair, a twin-child’; leth-eòlach, ‘half informed; half acquainted’; leth-oir, ‘sideways, edgeways’. All from leth, ‘half’.
Loppy filthy
lobh, “lo”, ‘rot, putrify’.
Lug to pull or tug Lugs knots in hair Lug ‘Oles ears (in the sense of handles that can be tugged)
lùgh, “lu”, ‘pith; strength; power of motion’.
Lurgi contamination, disease
luaireagan, ‘a grovelling person, a driveller’; luragach, ‘pretty; engaging, as a young female’. The term is used in the context of playground games: “You can’t play with us; you’ve got the lurgi!” could be used when excluding another child from a group. The meaning is not ‘disease’ per se but ‘femaleness’ in the context of self-segregation according to sex in childhood, which is important for boys because in mutually contesting to form all-male hierarchy they have to ensure this is completely separate from females so as to avoid any physical risk to them.
Maftin’ very hot
gu math teth ‘extremely hot’.
Mania as in “… got a mania for …”, a special interest or predilection for something, obsession
meànadh, ‘a foreboding, a foretelling’.
Manky ‘off’, disgusting
meangach, “meng’-ach”, meangail, ‘blemished, faulty’. 
Mardy moody, as in “stop being such a mardy bum!” 
mear-dhan, ‘fool-hardy’; maoidh, grudge, reproach, Irish maoidhim, grudge, upbraid, from Early Irish máidim, ‘threaten, boast’.
Marra a term of endearment
mo chara, ‘my friend’. [That the c is silent is attested by current Gaelic speakers.]
Marvellous great! [though instead this may be irony]
muirbhleachadh, ‘amazement’.
Mash to brew tea
masg, “masg”, ‘infuse; mix; steep malt for brewing’.
Mate, Matey very loose recognition of companionship
maothan, “mù’-an”, ‘a young person’, also meaning ‘the chest or breast’ — suggesting the notion of ‘bosom pal’. Alternatively or as a co-root, is maithean, ‘nobles, chiefs, heroes; the principal chief, or best of any class of beings’, for which maithe is short. This would be akin to the friendly deference shown in forms of address such as chief. There is also the general word maith, ‘good, fitting, convenient, having the desired qualities, useful, profitable, complete’. The t is silent in the Gaelic but this changes in an English context; presumably to fill the unexpected pause between the two syllables. 
Maungy whiny, sulky
meangach, “meng’-ach”, ‘crafty, deceitful, cunning’.
Mek Third Man a threat
maoitheadh, ‘threat’. The Anglicisation-cum-rationalisation seems to be conjuring an ally for an upcoming fight, nearly reflecting the original meaning.
Mester as in “mister”, and more specifically “little mester”, a handicraft knife-maker
measadair, “mess’-ad-àr”, ‘a valuer, an appraiser’, from meas, ‘respect, opinion’. A co-root specifically re Sheffield little mesters is meas, ‘point or edge; weapon’.
Mi’Sen myself
mi féin, ‘myself’.
Mind a warning to be careful, as in “mind how you go”
meanadh, ‘a foreboding, a foretelling’.
Mingin’ disgusting
meangach, “meng’-ach”, ‘blemished, from meang, ‘blemish, deformed’.
Mithering annoying or bothering
mi-thaitnich, “me-haejf-dyach”, ‘dissatisfy, displease, offend’.
Mizzle annoying fine light rain
misil, from mi, ‘disagreeable’, and sil , ‘light rain’.
Mockers as in “put the mockers on (something)”
moch-abachd, ‘early ripeness; prematurity’; moch-abaich, ‘soon ripe; premature, precocious’.
Molly-coddle
miodal, “med’-al”, ‘flattering, fawning, fair speech’ + cadail, ‘sleep’; i.e. miodal-cadail ‘soothing to sleep or good humour, by flattery, adulation, and fair words’.
Mope showing sadness
miapaidh, “meap’-e”, ‘sad; disgraceful’.
Morning the greeting
maidin mhaith, “mod-jin wot”. The second word, meaning ‘good’, is dropped. This better explains the standalone “morning”, since “good morning” surely would not lose its first word. The pronunciation “mod-jin” easily Anglicises to “morning”, but “morning what” would make no sense.
Muck dirt, in a wide sense
mugh, “mu” or “mù-gh”, ‘to begin to rot, decay, deteriorate’.
Mucker, Marra, Mi Owd … terms of endearment
mo chara, my friend’. These are various takes on the Gaelic through the passage of time; in the case of mucker the c not being silent.
Mug victim through own negligence
muig, “mueg”, ‘a discontented expression of countenance, a frown’; muigean, ‘a disagreeable, surly person, with a continual frown upon his face’.
Muggins complaint of being put upon
mùigean, “mueg’-aèn” (from muig), ‘a gloomy, churlish fellow, a grumbler’.
Muggy mildly oppressive weather conditions
muig, “mueg”, muigeach, ‘cloudy, dark, suffocating’; muigeil, ‘misty, dark, obscure, close; mùchach, ‘suffocating, stifling’.
Nang troublesome and irritating, as in “a nanglin’ task”
naosgair, ‘an inconstant man’, naosoaireachd, ‘fickleness, inconstancy’, naing, ‘mother’
Narky moody, sullen, sulky
nàrachadh, “nàr’-ach-a”, ‘the act of affronting or of disgracing, an affront; a disgrace; causing shamefullnss’.
Nesh to feel the cold all too easily
nàisgte, “naeshg’-tya”, ‘bound; tied; healed; secured’; perhaps related to nochd, ‘naked’. The meaning in Anglicisation is one of association: opting for well-wrapped clothing to protect all the time, whether it’s cold or not, indicates being all too ready to feel even the slightest degree of cold.
Nip to briefly be or go somewhere, as in “I’ll nip into …”
ni, ‘a deed, business, affair, circumstance, thing’.
Nipper child
cniopair, ‘a poor rogue’; neo-phrìs (i grave), ‘want of value; uselessness’.
Nithered / Nitherin’ strong wind, or its consequence of feeling cold
neatar, ‘strong, powerful’.
Noggin head
cnuachd, “kruachg”, ‘head, brow, temple, lump’.
Nous intuitive good sense or special access to knowledge
nois, ‘knowledge’.
Nowt nothing
nochd, “nochg”, ‘naked, bare, uncovered’. From old Irish nocht. This seems to be the source of ME naught.
Od Thi / ‘Old Yer as in “od thi dog back”, “‘old yer ‘orses”: wait a minute/slow down
oidherpeachadh, “aoerp’-ach-ag” ‘act of attempting’, from oidherp, ‘an attempt, endeavour, undertaking’.
Off going somewhere
falbh, “falv”, ‘a going, a retiring; a withdrawing; a departure’.
Oik
òg, òig, ‘youth’.
Oss make an effort, as in “oss thissen” 
aois, “aosh”, ‘always, ever, continually, on all occasions, still, all the same, ever afterwards, henceforward’; traceable back to Proto-Indo-European heyu, ‘long time, vital force, life, long life, eternity’. 
Owt something, anything: opposite of nowt
ogh, ogha, ‘whole, entire’.
Oyl, Coyl Oyl a windowless confined space, cellar; coal place (bunker) 
còil, òil, ‘a corner’ (softening of the c to ch leads to it’s loss, Gaelic ch being unpronounceable to English-speakers). It’s likely a tautology, ‘corner corner’, not referring to coal at all. Note that oil also is a word meaning ‘precipice’, so folk etymological humour may have been applied regarding what is a sheer drop down into a cellar, the bottom of which likely cannot be seen in the gloom for want of any window (ogluigh).
Pack It In stop it!
peacachaidh, “pechg-ach-a”,  ‘a sinning, a transgression’; peacaireachd, ‘the behaviour of a sinner’.
Paggered shattered, knackered, exhausted or broken
pògaireachd, ‘continual or frequent kissing’. Again, folk etymology not infrequently exhibits a sense of humour!
Pal a male-male friend, out of perhaps loose but nonetheless warm camaraderie
baigheil, “bi’-yhal”, ‘favourable, kind’, from baigh, ‘friendship, kindness, endear’. The accepted notion that pal is from Romani is likely through a confusion with Irish travellers, who would of course speak Gaelic, not Romani. That there is a similar word in Romani is likely through a common Proto-Celtic base.
Palaver a fuss
polaireachd, ‘a searching of holes and corners’.
The standard etymology is from Portuguese palarva, in turn from Latin parabola — and French parler would be invoked here — but these words all are specifically re speech when the sense of palaver instead is regarding all sorts of over-fussy activity. The original source of sailors would strongly suggest Gaelic, in that some of them would have been Irish.
Parched very thirsty
pàiteach, “pajt-ach”, ‘thirsty; a thirst, droughty; parched’.
Parky cold
pasgach, “pasg’-ach”, ‘wrapping, swaddling’. The usage here is indirect: cold weather is indicated in the need to tightly encase in clothing.
Peggy Tub washing container
pigean, “peg’-aen”, ‘a piggin, or small pail’; pìseagach, ‘in rags; in pieces, as cloth; ragged’. This is another name for a wash-tub to parallel dolly (tub). Whereas the latter was named from the sense of renewal in the washing process, here the vessel in named in terms of what is washed and/or the vessel itself. It’s the word for the clothes that surely is the primary root, as the notion of a small pail is not accurately descriptive, and seems to be evoked by pìseagach to then be recruited as a reinforcement (a secondary root).  
Perishing intensely cold
air reothadh, ‘frozen’.
Pillock
piolachair, ‘one who digs out of the earth’.
Plastered in a bad way physically, as when very drunk
plosgartaich, “plosg-art-ech”, ‘panting, gasping, throbbing’.
Playing (At) messing about or not doing what’s right, as in “what yer playin’ at?” 
pleadh, pleadha, “plé’-ag”, ‘a digging; a dibbling’; pleadhaich, ‘dig; dig out; work with a spade or dibble’.
Playin’ Pop to get angry with someone or tell them off
piollaisteach, ’vexing, annoying; that which vexes, troubles or teazes’, and/or piolaid, ‘pillory’. Pop as an additional element to piolaid or a reading of the last syllable of piollaisteach is likely from piob, ‘pipe, bagpipes, squeak’ (the piercing loud noise of the pipes being symbolic of a row). An alternative of the second element being Middle English poppe,’a blow, strike’, is thought to be onomatopoeic, which may simply take us back to piob.
Poll Thompson, as in ‘gee it some Poll Thompson’, meaning hammer it harder
piollaisteach, ‘vexing; that vexes or troubles; teazing; annoying’.
Pop / Bob (into)
beo, ‘alive, living; sprightly, lively’.
Pudgy a fat or chubby person 
bagach, ‘corpulent, bellying’.
Purler a brilliant shot with something
peileir, “pal’-aer”, ‘a ball; a bullet’.
Puther thick or smelly smoke
pùthar, ‘hurt, harm; a sore; a suppurating sore; a grievous wound; a cause of sorrow’; pùtharachadh, ‘suppuration’ (to discharge pus). This is an extension of meaning from the noxious liquid that may arise from a sore to the noxious thick fumes that may arise from a fire. In common is the notion of a harmful emanation.
Radged angry
riagh, ‘hang; crucify’.
Ravenous
reimhe, ‘fatness; grossness; pride’; reimheach, ‘arrogant, forward; petulant; conceited’; reimheachd, ‘arrogance, forwardness’.
Reckon to think or figure out
roighneach, “raòèn’-èch”, ‘choose, make a selection’.
Reek smoke
cruach, “kruach”, ‘heaps up’, is Anglicised to reek in several instances of steep-sided hills in Scotland and Ireland. The meaning of ‘heaps up’ denotes either a stack, which is a very steep-sided hill or pillar — a column of rock, indeed; or a rising column of smoke. The loss of the initial consonant is through lenition (softening) of the initial “c” > “ch”, which is unpronounceable by English speakers. Consequently Gaelic cruach becomes English reek.
Room used originally to mean the main room other than the house (the main, back living room cum kitchen).
rum, ruim, from Irish rum, with albeit manifest in Germanic languages like wise originally from Proto-Indo-European *rowə-, ‘free space’.
Round as in “I’m off round there’s”
raòn, raòin, “raon”, ‘a span’; rion, ‘a way, a road, a track’.
Ruarin’ crying
rughaich, ‘blush, flush, cause to blush’; ruaidh, ‘redden’; rortadh, ‘a flowing over’; ruamnach, ‘indignant, angry’.
Ructions a bit of a battle
raoic, ‘bellow, roar; belch’; raoicidh, ‘a bellow, a roar, raoichidh, ‘shall bellow’, raoichdeach, ‘bellowing, roaring; making a belching noise; flatulent’ (and several similar words).
Rum as in “rum job”, “rum ‘en”
ròmach, ‘hairy; rough; bearded; shaggy’; ruaimneachd, ‘strength, robustness, activiity’.
Russle (Up) quickly but carelessly produce something
ruiseil, ‘rash, hasty, precipitate’.
Sam Up to collect together
samhadh, ‘a congregation’.
Sarnie sandwich
saorsanach, ‘a helper a work, an unhired workman’.
Scran food
sgrathan, “skra-ann”, ‘peelings’, is Mackay’s suggestion, though it may be (or may be reinforced by) what is also the derivation of scroam (below): a word denoting small food items, sgròim. It also could derive tangentially from sgoirn, sgornach, ‘a throat, windpipe, gullet’.
Screw loose something wrong in behaviour/mentality
sgiurloing, ‘a fugitive; a deserter’.
Scroam(in’) ungainly movement in close contact with the ground, getting dirty in the process
sgròim, ‘non-specific term for a variety of small crustaceans (e.g. barnacles, small mussels and whelks) used for pounding into groundbait or chum; small/loose change’. The sense is of getting down and dirty for no good reason: to find nothing of value or consequence.
Sen self 
in, “fein”, ‘self’mi féin, ‘myself’; thu féin, thyself’.
Settee chair, a sofa
seithir, ‘a chair; especially a long chair’. It’s a sofa, but settee was always the word I heard locally.
Set-to a proper sorting-out, as in “a right set-to”
seòltachd, “shyol-ttachg”, ‘method, arrangement, guile, artfulness, wiliness, ingeniousness’.
Sharp act nimbly, with speed or guile, as in “look sharp!”
sèap, “shep”, ‘sneak; slink; pursue closely’.
Shit a bad person
siota, ‘an ill-bred child, a petted or spoiled child’.
Show as in “you’re all over the show”
seo, “shyo”, ‘this’ or ‘here’.
Sickening ill
seac-theinn, ‘a severe illness’; seachdachadh, ‘a growing withered’; seochlanachd, ‘feebleness and awkwardness, physically’; seòganaich, ‘a shaking to and fro; a hobbling’; sic, sichd, ‘a sudden personal onset; a sudden effort to take hold of one’.
Side put away in its proper place
saoid, “saod”, ‘a state or condition; care; attention; a track or journey’.
Silin’ raining heavily, as in “it’s silin’ it down!”
sìl, “shè’l”, ‘shower; rain in heavy showers’; sìleadh, ‘heavy showers’.
Sitting Room lounge, front room, Settee
seithir, seithreach, ‘a chair; a coach or chaise’; seathar, ‘a library; a study’; perhaps also sioth, written also sìth, ‘peace’.
Skift to move 
sgapte, ‘scattered, spread abroad, dispersed, routed’; sgiap, ‘sweep off; carry off swiftly’.
Smashin’ / Ma Son as in ”that’s ma son!”
is maith sin, “iss MY shin” or “iss MAA shin” > “smoy shin”, ‘that’s good’.
Snap food, particularly provisions for such as a lunch away from home, but food generally
cnuasachadh, ‘provision(s)’, in the sense of preparation; literally ‘a gathering or scraping together’. With a pronunciation well outside English expectation, that to an English ear is little more than ”k-na?”, a rationalisation to a nearest-sounding English word yields “snap”.
Snazzy neat dress sense
snas, “snás”, ‘decency; regularity; elegance; neatness’.
Snek door threshold in the sense of the door almost closed, only fractionally ajar, or closed but not securely so, as in “on’t’sneck”
snaig, “snaeg”, ‘latch or sneck of a door’; sneag, ‘a notch, a nick; a dent, a cut’.
Snicket alleyway, cut-through
snàig, “snàeg”, ‘creep, crawl, sneak; steal softly’; snàigidh, ‘shall creep’; snàigeach, ‘creeping, crawling, sneaking; having a creeping gait’; sneagach, ‘notched, notching’; sneagaich, ‘notch; dent, indent’; sneag, ‘a notch, a nick; a dent, a cut’.  snitheach, ‘oozy’
Snidered snowed under
sniaghtey, ‘precipitation of snow’. ‘Snidered out’ denotes being unable to access somewhere for its being full of something, as in being hemmed in by snow.
Snot nose secretions
snot, ‘smell, snuffle, snort’.
Spas / Spaz falsely thought to be short for ‘spastic’
spaisean, ‘a term of contempt for a boy’.
Spell / Spelk splinter 
spealg, “spyallg”, ‘a splinter, a fragment’.
Spice sweets
spéis, “spash”, ‘liking, fondness’. With sugary confections a recent phenomenon, there was no word for them from Gaelic, so a word was used with tangential meaning.
Spinny a small area of bushes or bushes with some trees
spruanach, ‘abounding in brushwood’.
Spoz lucky
soirbheas, “soer-as”, ‘luck, luckiness’; soirbheasach, ‘fortunate’. A contraction of this.
Sprog child
spreigh, ‘burst suddenly, disperse, scatter, separate, part’. A word denoting the act of childbirth.
Stick as in “gee it some stick!”
stuig, “stueg”, ‘incite or spur on to fight, as dogs’.
Struth an exclamation, mistaken for a contraction of “God’s truth”
struidh, “strue-y”, ‘spend, squander, waste’.
Sup (& Swig) sip
sùbh, sùgh, ‘juice’; sùigh, ‘suck’.
Swill drink
sruthail, “sru’l”, ‘wash, rinse’. [A large number of very closely related words]
T’t’ on the way, falsely assumed to be ‘to the’
tigheachd, ‘coming, arriving; an arrival, an approach’. Often contracted to teachd. From teach, ‘house, dwelling-place’.
Tackle male genitalia
teaghlach, ‘a family, clan, race, progeny’.
Tanking as in “tanking along”’ or “tanking it”: moving quickly
teangach, “tyeng-ach”, ‘having many tongues, loquacious’. The notion of excessive talking has been applied more generally. This is nothing to do with the usual meaning of “tanked” of failure.
Tat anything in poor condition or of low quality
taisgte, ‘hoarded, laid up, buried’.
Tatied very tired
teadalach, ‘slow, dilatory, sickly’.
Tea-time the early evening meal to follow what still nowadays though more so of old was the main one of dinner, which it was thus called, not lunch.
tioidhte “tyoe-y-tyer”, ‘warmed, simmered’; teotachain, ‘warming-pan’; teothadh, aidh, ‘a warming, a chafing, a heating’. … several inter-related words; from teò, teoth, ‘warm’; with teol, ‘plenty, substance’, a possible co-root.
Teem to rain heavily, to abound with something, as in “its teeming down” (with rain)
taom, “taom”, ‘a shower of rain’. This word is also used to describe the molten metal flowing when a steel furnace is tapped.
Think-on remind
thoir an cuimhne, ‘remind’.
Thissen yourself
thu féin, ‘thyself’.
Thoil couldn’t bear to, as in “I couldn’t thoil it’, meaning being reluctant to pay the asking price or referring to something not being worth the asking price.
dhiol, ‘paid; restored; avenged’. [dh is a soft th sound.]
Tick debt, as in “on’t tick”
tiag, or tiach, ‘purse, wallet, money’, tiachdaidh, ‘a customer’. In the Gaelic context initial ti is pronounced like “jack”, but Anglicisation softens this.
Titivate
tathaicheadh, ‘a frequenting, a visiting; a craving’; taothaill, ‘a frequenting, a haunting, a visiting’; toicheumach, ‘gradual, step by step’; titheach, ‘eagerly; desirous; eager; keen; earnest; willing; sharp; forward’; taitinn, ‘please, satisfy, be acceptable’. A number of words inter-related in both meaning and sound indicate a word-family source here.
To-do as in “a to-do”, a big fuss
taidhean, ‘a troop, a multitude, a cavalcade’.
Traips tread heavily, as in “I’m fed up o’ traipsin’ roun’ shops”.
treabh, “trav”, ‘plough’. The drag on progression provided by the earth in the act of ploughing is akin to begrudgingly going somewhere.
Tranklements belongings, especially in the sense of burdensome clutter you’re obliged not to be rid of
tearraideach, ‘of, or belonging to’; tearuinteach, ‘protecting, preserving, saving’; teirinn, ‘descend, come down’ (note nn sounds “ng”). A grammatical construction from these inter-related terms regarding possessions, with no doubt English embellishment, and perhaps intended humour.
Turn as in ‘a turn’
tùrn, tàirn, ‘a job, a work, a turn’.
Tussle a protracted little battle, whether physical or not
tuasaid, “tuas-aj”, ‘squabble, fray, or quarrel; a wrangle; a fight; contention’.
Twig know
tuig, “tueg”, ‘know’.
Tyke man, Yorkshire person
taig, “taeg”, earlier tadhg (still earlier, proto-Celtic *tazg(j)o-) ‘poet’ or ‘storyteller’. The name Tadgh, “tie-ge” (Anglicised as the surname Teague), was so common from the 16th century in Scotland and Ireland that it became the generic word for a man.
Ummer (It)  as in “gu ter ummer”, “bloomin / flippin ummer”. Supposedly a ‘minced oath’, as with ee by gum and by ‘eck’. Held by some to mean ‘bother’.
ubagaich, “ub-ag-ach”, ‘subdue by charms or spells’; ùmaid, ‘blockhead, fool, simpleton’.
Umbrage to hold a grudge, as in “to take umbrage”
uaibhreach, “uaev-ryach” ‘proud, haughty, insolent’; uaignidheach, ‘lonely, solitary, deserted’; uamhannach, ‘dreadful, terrible, horrible, shocking’; uamharradh, a. ‘proud; abominable; direful; disgustful, loathsome, excessive’.
Un one, as in “he’s a reight un, that un”
Old Irish oin, ‘one’, from Proto-Celtic oinos, ‘single, one’; ur, ‘a child, person’.
Up as in “I’m off up’t’road”
uapa, composite pronoun ‘from them, from amongst them; away from them’.
Waller person
uaislichte, “uaeshl-ashg”, ‘ennobled, exalted, dignified’, uaislean, ‘gentry, nobility, nobles; uasal, a nobleman, a gentleman; uais, ‘noble, well descended’; uaIsle, ‘nobility’.
Wally a very mild, even affectionate derogation 
uaill, “uaelly”, pomp, vanity, inconsistent boasting’; uailleag, ‘conceited female’.
Wammy queasy, feeling unwell.
uam, “vuam”, ‘away from me’; and surely also related to weam, ‘belly, stomach’ (from uamh, ‘cave’). Note v  often becomes or is taken to be “w”.
Wang to throw
uainn, “vuaen”, ’from us’ (nn in Gaelic trends to become “ng”, and, again, there is v > “w”).
Watter water
bathadh, “ba’-a”, ‘a drowning, a quenching, a slaking’. [Aspirated b: bh, “w”; and presumably the pause between vowels to an English warrants a consonant]
Way’od or Way’up wait, hold up or hold on
éigheach, ‘a call’; this is a slight variation in pronunciation of eh up. It’s a general hello there!’
Welly as in ‘gee it some welly’
uile, “u’la”, ‘all, whole, every’; from Proto-Celtic *olyos (‘all, whole, every’). The sense here is of giving it your all; giving it everything.
Wheedle / Wangle to try to lever this way and that
uideal, ‘a wavering, a tottering; a moving to and fro’.
While until, as in “I’m working while six tonight”
uile, “u’la”, all; whole; every’, from Proto-Celtic *olyos, ‘all, whole, every’, related to ball, ‘immediately, on the spot’, uair, ‘time’, and iomall, ‘a border, a boundary, extremity, verge, frontiers’ (‘extent’).
Whist be quiet!
eisd, “ashjj”, ‘listen’.
Wick lively
Old Irish uic, from Proto-Celtic *ōnkeyo-‎, ‘causative of’, *ēnko-, from Proto-Indo-European *h₂neḱ-‎, ‘to reach’; uic, ‘comes’, -icc or ucci, ‘reach, attain’.
Wittle, Wittlin’ worry, also paring down with a knife
uideal, eil, s.m. ‘a wavering, a tottering; a moving to and fro; jeopardy’, with uile-iomlan, ‘all-perfect’.
Yips sudden loss of skill through nerves
iurpais, ‘restlessness, fidgetting’.
Yonder over there, likely some considerable distance
ionad, “eun’-ad”, ‘place, abroad’.
Yonks / Donkeys Years a very long time
ùinc, ’distance’, in the sense of ‘space of time’. Donkey is simply the nearest word in English sound-wise.
uapa, composite pronoun ‘from them, from amongst them; away from them’.