Green’s Dictionary of Slang

bad boy n.

[bad adj. + SE boy]

1. (mainly W.I., Guyn., also bad bwai, bad bwoy) a tearaway, a young criminal; in positive version, a black who rejects the second-class role offered by the dominant white society.

[US]E. Booth Stealing Through Life 250: ‘Where’s Peck’s bad boy?’ the sheriff called into the cells.
[UK]C. MacInnes ‘A Short Guide for Jumbles’ in England, Half Eng. (1960) 26: A peculiarity about any coloured ‘bad boys’ one may encounter is that [...] they often seem delightful personalities.
[US]D. Woodrell Muscle for the Wing 28: He wore a black coat with narrow lapels, a white shirt and a string tie, all in accordance with the resurging style of the rockabilly bad boy.
[UK](con. 1979–80) A. Wheatle Brixton Rock (2004) 3: Feeling he must keep up his ‘bad bwai’ pose [etc.].
[UK]Guardian Rev. 3 July 9: The burgeoning attraction between her and Orin, a young ‘bad bwoy’.
[UK]Indep. Rev. 25 June 12: Some astonishing Jamaican gangster sequences featuring a hilarious Kingston bad-boy called Lennox.
[US]W. Shaw Westsiders 269: The trouble is, Sneak has been a bad boy for too long.
Stormzy ‘Shut Up’ [lyrics] If you got a G-A-T bring it out / Most of the real badboys in the south.

2. (US black) a general term of approval, referring both to individuals and to objects.

[US]L. Durst Jives of Dr. Hepcat (1989) 9: When I pin you daddio the wagon in here, and you lodes my heart on. You don’t pack no six gun, but you are a bad bad boy, and for you my lid always flip.

3. (US) anything considered impressive.

[US]R. Price Breaks 156: Tell them to get it the hell out of room 220 so I can move in the way I was supposed to, and this bad boy’s yours.
[US]D. Simon Homicide (1993) 323: I saw an ad for one of these bad boys [i.e. a gun].
[US]R. Price Clockers 224: If I did [have a gun] I’d sell it [...] I’d sell the shit out of that bad boy.
[US]D.H. Sterry Chicken (2003) 82: Ya better git that badboy [i.e. a large penis] out, or there’s gonna be trouble here ta-night!
[US]Simon & Alvarez ‘Backwash’ Wire ser. 2 ep. 7 [TV script] You get this bad boy [i.e. a concealed microphone] within ten feet of any conversation, asounds like Chuck thomspon doing play by play.
[US]C. Hiaasen Nature Girl 235: I could inhale a whole box of those bad boys [i.e. doughnuts].
[SA]Cape Argus (SA) 31 Jan. [Internet] Grand Cherokee a bad boy among SUVs.