Publishing history:v1.0
v1.0: 29/04/26
sleamacair m. *[ˈʃʎɛ̃maɡ̊əɾʲ], 
Cf. [ˈʃlʹɛmɑkəð] (Faclan bhon t-Sluagh˄: Lewis).
Although MacLennan inadvertently describes sleamacair as an adjective.
The word slæmr is unattested in Old Norse and was no doubt drawn by Mackenzie from Cleasby’s (1874) Ice. slæmr, in the metaphorical sense ‘vile, bad’. At any rate, ON æ [ɛː] would be expected to yield SG [ɛː] or (broken) [ia], not short [ɛ]. It seems likely that SG sleamagair goes back to Scots slammack in the senses ‘a hasty mouthful of food, a snatch or gobble of food; a piece or portion, especially of food, seized by force or taken on the sly’ and, as a verb, ‘to take food furtively, to sneak titbits from the table; to lay hold of anything by means not entirely fair or honourable’ (SND˄, s.v. slammach; hence SG slamag ‘a slug (of liquid)’, cf. Faclan bhon t-Sluagh˄) + the Scottish Gaelic agentive suffix -air.
The nature and origin of the suffix is problematic. For -[əɾʲ] in peripheral dialects, perhaps the result of confusion between the agentive suffixes -air -[aɾʲ] and -aire -[əɾʲə], see Ó Maolalaigh 2013, 210–13; cf. duil fhear (*duilear), ealbhar and slabhcar.
Of Jonathan Swift’s 1726 Gulliver’s Travels, Grennan (≈1945, 201 fn 15) writes that ‘[o]ccasionally there is bait for the ingenious in such remote but provocative resemblances as the Irish [leg. Scottish Gaelic 
Neither sleamacair nor tramailteach appears to be attested in Irish.
Although influence from an (Antrim) Irish plural -an (cf. Holmer 1940, 44–46 + Note, for the Glens of Antrim, and 1942, 76–84, for Rathlin; and cf. SG -an, Mx -yn) should perhaps not be ruled out. In 1695, Swift was appointed prebend of Kilroot, in County Antrim, in the cathedral of Connor: ‘[i]n this sparsely populated, isolated, neglected, and overwhelmingly Scottish Presbyterian parish he was installed on 15 March’ (Probyn 2004); although he did not resign from Kilroot until 1698, Swift returned to England the following year (ibid.). For Swift’s view of the Irish language, see his On Barbarous Denominations in Ireland (in Scott 1905, VII, 343–50, also available at CELT˄).