Green’s Dictionary of Slang

1. a short iron crowbar, used by criminals.

1848		‘Ned Buntline’ Mysteries and Miseries of N.Y. V 49: The foremost villain [...] broke down her guard with a short iron crowbar, or ‘billy,’ as the burglars term it.
1851		‘Greenhorn’ [G. Thompson] Bristol Bill 21/1: [T]hose singular specimens of ingenious mechanism — ‘billies’ and ‘jimmies,’ ‘jacks,’ ‘braces,’ and ‘bits,’ — that have [...] formed the paraphernalia of a burglar’s outfit.
1930		A. Carey Memoirs of a Murder Man 6: The detectives ran their hands through the pockets [...] of their prisoners and out upon the high desk tumbled rings and watches, money, nippers, keys, billies, jimmies, gold bricks, and the other paraphernalia of the thief.

2. (UK Und.) stolen metal.

1864		Hotten Sl. Dict. 74: billy stolen metal of any kind.
1873		Sl. Dict.
1889–90		Barrère & Leland Dict. of Sl., Jargon and Cant.
1890–1904		Farmer & Henley Sl. and Its Analogues.
1895		Crowe Aus. Sl. Dict. 8: Billy, stolen metal.

3. (orig. US, also bill, billie, billy club, billy stick) a policeman’s wooden club (orig. untanned cowhide, covered in wool).

1842		N.Y. Herald 2 Feb. 2/4: Van Dyke made fight, and although Bowyer used his ‘billy’ with all the force in his power, he was getting rather the best of him, when officer McGrath came to his assistance.
1856		G.G. Foster N.Y. by Gas-Light (1990) 144: The rattling of the policemen’s ‘bills’ upon the heads and bones of the rioters.
1866		H.L. Williams Gay Life in N.Y. 72: If he don’t come quietly, use your billy!
1873		Sl. Dict.
1887		G. Devol Forty Years a Gambler 147: I began to lay them out as fast as I could with the billy.
1892		W. Norr Stories of Chinatown 51: The fellow who had his nut opened swore positively I was the man [...] who had hit him with a billy.
1901		C.R. Wooldridge Hands Up! 72: He received an electric shock from Wooldridge’s billy, which struck him under the ear.
1911		‘Madge The Society Detective’ in Roberts et al. Old Sleuth’s Freaky Female Detectives (1990) 106/1: She slugged me [...] She used a billy, that’s what she did.
1916		J. Lait ‘Charlie the Wolf’ in Beef, Iron and Wine (1917) 55: With a billy an’ a gun an’ a pair o’ bracelets youse see to it that shoe clerks don’ spit on the sidewalks.
1928		J. Callahan Man’s Grim Justice 32: He suddenly whipped a ‘billy’ out of his pocket and banged me over the head.
1934		(con. 1920s) J.T. Farrell Young Manhood in Studs Lonigan (1936) 255: He [...] belted the guy with the billy, flush in the mouth.
1942		N. Algren Never Come Morning (1988) 107: He knew now he was going to be beaten [...] with keys or hose or billy.
1953		F. Paley Rumble on the Docks (1955) 98: Jimmy clipped him alongside the ear with the billy.
1957		D. Burley N.Y. Amsterdam News 6 July 13: A few strokes of the billy stick.
1965		C. Brown Manchild in the Promised Land (1969) 20: They [i.e. policemen] would always promise to beat us over the head with a billy.
1980		E. Folb Runnin’ Down Some Lines 229: billy [...] 2. Police riot stick.
1980		Maledicta IV:2 (Winter) 194: We also find the policeman represented with his truncheon, billie, night stick or copper stick (which is also a housewife’s tool of the last century).
1987		T. Wolfe Bonfire of the Vanities 562: What an amazing array of stuff the cops carried on their backsides. Billies [...].
1995		Luther Allison ‘Big City’ 🎵 Evening sun going down, police using his billy stick.
2012		T. Piccirilli Last Kind Words 20: Her parents [...] shoved up against the wall, frisked, billy-clubbed in the kidneys, cuffed, Freeze, dirtbag.
2018		‘Aidan Truhen’ Price You Pay 31: They get me coming out of the elevator. Heavy hands and a billy club or a real old-fashioned sap.

4. a form of blackjack, usu. ‘loaded’ with lead.

1842		N.Y. Daily Express 8 Oct. 2/5: He also had concealed in his sleeve a most formidable weapon called a ‘nimble billy,’ eighteen inches long, to each end of which was attached a leaden ball weighing about a pound.
1847		Sun. Times and Noah’s Weekly Messenger (N.Y.) 9 May 2/3: Hodgkiss was struck by a slung shot — a beastly, unchristian and murderous affair, familiarly called ‘a billy,’ which is a corruption of the French term bille.
1859		Matsell Vocabulum 11: billy. A piece of whalebone or raw-hide about fourteen inches long, with an oval-shaped lump of lead at each end, one larger than the other, the whole being covered with buckskin or india-rubber.
1879		Nat. Police Gaz. (NY) 13 Dec. 10/3: He is at once either chloformed or put to sleep with a sand club or ‘billy’.
1901		C.R. Wooldridge Hands Up! 264: McGinnis pulled a piece of garden hose filled with shot from his pocket and used it as a billy.
1905		H. Green Actors’ Boarding House (1906) 31: Feeling in his pocket for the short billy.
1909		I.L. Nascher Wretches of Povertyville 31: Criminals occasionally use a [...] loaded billy [...] a small club with a piece of lead in a cavity in the lower end.
1921		P. & T. Casey Gay-cat 245: In the hip pocket of Charley Small he found a billy of lead.
1924		D. Hammett ‘Nightmare Town’ in Nightmare Town (2001) 37: Mrs. MacPhail bent over his head, raising the black leather billy she still held [...] the down-crashing blackjack fell obliquely on his shoulder.
1930		C.R. Shaw Jack-Roller 144: We had to give them a tip on the head with our ‘billy’ or give them the strong arm to avoid noise.
1947		F. Brown Fabulous Clipjoint (1949) 51: The heister came up on him, knocked off his hat with one hand and swung the billy with the other.
1952		N.Y. World-Telegram and Sun 30 Dec. n.p.: On the floor of a powder blue convertible that carried the five attackers [...] police found a billy, two lengths of rubber hose, two screw-drivers and three bumber guards.
1966		H.S. Thompson Hell’s Angels (1967) 133: Any blackjack, sling shot, billy, sandclub [...] and firearms of any type.
1973		E. Droge Patrolman 25: All [police] uniform pants are equipped with two extra pockets in the rear for flashlight and billy, a nine-inch, hard-rubber club.
1977		B. Jackson Killing Time 233: I flinched in spite of myself when they hit him with a billy.

5. (US) a police officer; the police as a group.

1968		in DARE.
1980		E. Folb Runnin’ Down Some Lines 66: The characterization of the police [...] connotes such perceived attributes as brutality (billy for billy club, mallet, whup-a-child).

6. (US prison) a white man.

2000

Other Side of the Wall: Prisoner’s Dict. July 🌐 Billies: White men.