tack, n.⁴ — Green’s Dictionary of Slang

tack n.⁴

[? SE tacit, silent]

(US black)

1. a conservative, by. ext. a fool.

1974

cited in C. Major Juba to Jive (1994).

2. an unsophisticated person.

1995

A. Higgins Donkey’s Years 144: Certain Lower Line tacks had dry-bangs (a ride without the trousers removed) with passing Third Line sows.

3. a clever person [also note phr. smart as a tack].

1972

D. Claerbaut Black Jargon in White America 82: tack n. a clever or smart man.

on the tack (adj.) [? rhy. sl.]

(UK milit.) teetotal, thus off the tack, back to drinking.

1894		Civil & Milit. Gaz. (Lahore) 18 Oct. 4/3: I’ve gone on the tack Bill, since April / That’s news.
1896		‘Army Slang’ in Regiment 11 Apr. 31/2: A teetotal [soldier] is ‘on the cot,’ ‘on the steady,’ ‘on the tack,’ ‘on the dead,’ or has ‘put the peg in’.
1900		Regiment 27 Jan. 288/1: When a soldier has become a teettaller [...] he is said to be ‘on the tack,’ ‘up the pole,’ or ‘on the dead’.
1900		Regiment 27 Jan. 288/1: [S]hould he happen to be induced by a chum to ‘have a wet,’ he is said to have ‘broke out,’ or ‘gone off the tack,’ or ‘broken the teapot’.
1935		Thieves Slang ms list from District Police Training Centre, Ryton-on-Dunsmore, Warwicks 7: On the tack: To abstain from alcohol.
2015		L. McInerney Glorious Heresies 118: ‘I’m in here on the tack because that’s a hell of a lot easier for the State to deal with’.