Green’s Dictionary of Slang

1. (also nuck) a pickpocket or thief; also attriib.

1812		Vaux Vocab. of the Flash Lang. in McLachlan (1964) 249: knuck, knuckler, or knuckling-cove a pickpocket, or person professed in the knuckling art.
1834		(con. 1737–9) W.H. Ainsworth Rookwood (1857) 177: The knucks in quod did my schoolmen play.
1848		‘Ned Buntline’ Mysteries and Miseries of N.Y. I 40: You’re as good a knuck as ever frisked a swell!
1856		Nat. Police Gaz. (NY) 13:33 3/1: These knucks are constantly at work at tippling places, short go-aways, break-ups, dry-goods trips, and especially where they go to see the elephant.
1865		Leaves from Diary of Celebrated Burglar 9/2: Joe Belton was only beginning his career as a ‘knuck’ at the time.
1866		Night Side of N.Y. 78: The houses were so well patronized by ‘knucks’ and ‘cracksmen’ that the landlords never took any responsibility.
1877		R. Burdette Rise and Fall of the Mustache 141: That infamous organization of political thieves, knucks, outlaws.
1882		Nat. Police Gaz. (NY) 2 Sept. 10/3: The entire mental Intelligence of the ‘knuck’ fraternity of the world seems centred on New York.
1889		S. Bailey Ups and Downs of a Crook’s Life 32: Hughy Kelly, better known as ‘Blinky,’ a notorious ‘Knuck’.
1893		Congressional Record H. R. Rep. 2242/2: They employ knucks [DA].
1895		C. Crowe Aus. Sl. Dict. 43: Knuck, a pickpocket;‘knucks works the turf for leather and skins,’i.e., pickpockets at races to steal pocket books and purses.
1904		Number 1500 Life In Sing Sing 251: Nuck. A thief.
1908		‘The Great Bond Robbery’ in Roberts et al. Old Sleuth’s Freaky Female Detectives (1990) 62/2: It is the resort of sporting men and ‘knucks’.
1912		Buffalo Courier (NY) 8 Sept. 67/3: The ‘knuck’ had plenty of work.
1927		‘Jargon of the Und.’ in DN V 453: Knuck, A pickpocket.
1935		A.J. Pollock Und. Speaks n.p.: Knuck, a thief.
1949		Monteleone Criminal Sl. (rev. edn) 164: nuck A thief.

2. (US) in pl., the knuckles.

1858		G.W. Harris ‘Sut Lovingood’s Adventures in New York’ N.Y. Atlas XXI Aug. in Inge (1967) 140: I split hit onter his nose, an’ two ove my ’nucks went inter each ove his red eyes.
1908		L.W. Payne Jr ‘Word-List From East Alabama’ in DN III:iv 327: knucks, n. [...] 2. The knuckles. ‘He hit me on the knucks.’.
1935		S. Kingsley Dead End Act II: No bottles ’r rocks, jus’ sticks ’n’ bare knucks.
1955		B. Appel Tough Guy [ebook] Clip was the roughneck leader, Kid Knucks himself.

3. (orig. US, also brass knucks, nucks) usu. in pl., brass knuckles, worn over the fist to ensure victory in a fist fight [abbr. knuckleduster n. (1)].

1861		Jrnl. House of Reps (KY) 22 Mar. 339: And there shall also be exempted from execution one bowieknife, one six shooter, and one pair of brass knucks.
1867		Reports of Cases Argued (IN Supreme Court) 28 311: One of these witnesses testified that he distinctly saw something in Heffren's hand, which he took to be ‘brass knucks’.
1878		Edward Shippen Thirty Years at Sea 164: I hope you’ve got your brass ‘knucks’.
1886		Dly Teleg. (Monroe, LA) 16 Mar. 1: One of them struck Stanton on the temple with a pair of brass knucks.
1898		Kansas City Jrnl (MO) 28 Mar. 3/2: The gang [...] beat us up with their fists. The fellow that struck me used ‘knucks’.
1903		Ade ‘Why “Gondola” Was Put Away’ in In Babel 45: He made a deeper reach [i.e. in his pocket] and found a brass ‘knucks’ with a blunt head and three staring finger-holds.
1910		‘O. Henry’ ‘Compliments of the Season’ in Strictly Business (1915) 202: Mike relied upon a pair of brass knucks.
1916		J. Lait ‘The Gangster’s Elegy’ in Beef, Iron and Wine (1917) 242: He carried his brass knucks in his pencil pocket.
1925		G.H. Mullin Adventures of a Scholar Tramp 285: De dinge slowed ’in wid a pair o’ brass knucks.
1927		(con. 1890s) H. Asbury Gangs of N.Y. 276: ‘I only give her a little poke,’ he exclaimed. ‘Just enough to put a shanty on her glimmer. But I always takes off me knucks first.’.
1934		(con. 1920s) J.T. Farrell Young Manhood in Studs Lonigan (1936) 191: I’m getting me a nice pair of brass knucks.
1939		Howsley Argot: Dict. of Und. Sl. 35: nucks – see ‘knucks’.
1947		I. Shulman Amboy Dukes 116: Carrying a knife and knucks is like wearing peg pants and a sharp hat.
1948		R.L. Bellem ‘Death Ends the Scene’ Hollywood Detective May 🌐 Tough muggs who were plenty handy with brass knucks and blackjacks.
1949		Monteleone Criminal Sl. (rev. edn) 164: nucks Brass knuckles.
1953		Kramer & Karr Teen-Age Gangs 60: Ya ever see a guy hit with knucks?
1957		H. Simmons Corner Boy 117: The other two groups got three blades and a knuck.
1959		W. Brown Teen-Age Mafia 7: Walk into a liquor store and work over the stud behind the counter with a pair of brass knucks.
1968		L. Wolf Voices from the Love Generation 251: Hillbilly kids that went to war with shotguns, bicycle chains, brass knucks.
1971		T. Thackrey Thief 358: No guns, no shanks, no brass knucks.
1980		(con. 1940s–60s) H. Huncke ‘Detroit Redhead’ in Eve. Sun Turned Crimson (1998) 105: She opened her purse and took out a pair of brass knucks.
1990		(con. early 1950s) J. Ellroy L.A. Confidential 28: Sten hit the #4 cell – waving brass knucks.
1992		Bentley & Corbett Prison Sl. 87: Knucks Any type of brass knuckle or metal finger coverings used for fist fighting.
2001		(con. 1964–8) J. Ellroy Cold Six Thousand 6: Fuck – knives in his boot tops. Brass knucks in one sock.
2023		(con. 1962) J. Ellroy Enchanters 8: I slid on my brass knucks and kidney-punched him.