Green’s Dictionary of Slang

1. a blow; lit. and fig.

1820		‘Peter Corcoran’ ‘King Tims the First’ in Fancy 45: I must fight! / Jenks! we must feed on Honour’s slugs to-night.
1882		‘The Jargon of Thieves’ in Derry Jrnl 8 Sept. 6/5: A blow of the fist or a club is a ‘slug’ .
1887		G. Devol Forty Years a Gambler 103: I [...] hit him a slug in the ear that curled him up on the floor like a possum.
1914		H. Hershfield Abie the Agent 25 Mar. [synd. cartoon strip] — Is that his joint, Mister Slugslinger? — We’ll ride by slowly.
1931		O. Strange Law O’ The Lariat 76: A gent what gets a slug like that has gotta fall somewheres, ain’t he?
c.1950		K. Howard Small Time Crooks 29: Have you gotta pet kinda slug, a real sock that people might know you by?
1960		E. De Roo Big Rumble 8: Put the phone out of order with slugs.
2001		(con. 1964–8) J. Ellroy Cold Six Thousand 257: Jimmy took another slug — pension-fund fraud — two five-year terms concurrent.

2. (US) a person.

1909		Eve. Star (Wash., DC) 11 Sept. 20/1: It’s a film that shows a swell slug that’s lost his wad and gets down to carrying the banner or something.
1940		S. McBarron ‘Coffin Custodian’ Ten Detective Aces Apr. 🌐 I’m a pretty heavy slug, and I was suspended in such a manner that my toes barely touched the floor.
1943		R.L. Bellem ‘Heads You lose’ in Dan Turner Hollywood Detective Feb. 🌐 I plunged at the chunky slug but he got away from me.

3. (US Und.) a blackjack.

1929

C.G. Givens ‘Chatter of Guns’ in Sat. Eve. Post 13 Apr.; list extracted in AS VI:2 (1930) 134: slug, n. [...] a blackjack.

4. a thug.

1944		C.S. Montanye ‘Publicity for the Corpse’ in Thrilling Detective Dec. 🌐 Thinking about [...] a punk with a funny, crinkleskinned pan and another slug with a round, moony mush.
1958		R. Prather Scrambled Yeggs 125: ‘Jug!’ The word snapped from the throat of the big slug on my left.
1983		A. Payne ‘Get Daley!’ Minder [TV script] 67: I want to be on the spot when he nicks that slug.
2000		T. Fontana ‘Works of Mercy’ Oz ser. 4 ep. 4 [TV script] We can make a lot of money renting that phone out to the slugs round here.

5. (N.Z./US) in fig. use, a payment, usu. seen as an excessively high price.

1958		Bridgeport Post (CT) 27 July 32/9: What most people don’t realize is that they pay a large slug of taxes when they buy a new car.
1989		Springfield News-Leader (MO) 2 Aug. 1/2: I’m going to pay a slug of tax.
2001		Guardian 14 Apr. 27/2: Tesco does not recycle all its profits. It pays a slug of them out in dividends to its shareholders.
2003		McGill Reed Dict. of N.Z. Sl. 192: slug Exorbitant price applied ANZ c.1920.