Green’s Dictionary of Slang

tack n.2

[SE tack, an alien, odd or unpleasant flavour; ? ult. Lat. tactus, infection]

(later Irish) anything mouldy or sour, esp. a taste (in food or drink) that is other than one expects.

[UK]Hotten Sl. Dict. 252: tack a taste foreign to what was intended; a barrel may get a tack upon it, either permanently mouldy, sour, or otherwise.
[UK]Sl. Dict.
[Ire]‘Flann O’Brien’ At Swim-Two-Birds 223: I’ve had an odd pint of that tack in my time.
[Ire]B. Behan ‘The Confirmation Suit’ After the Wake (1981) 40: They tasted it [...] Some said it was paste [...] and there were other people who maintained it was glue. They all agreed on one thing, that it was dangerous tack to leave lying around.
[Ire]B. Behan Brendan Behan’s Island (1984) 150: It was dangerous tack to leave lying around, where there might be young children.
[Ire]Share Slanguage.