Green’s Dictionary of Slang

bad-ass adj.

[bad-ass n.; given the use of bad, the term is as much congratulatory as not]
(orig. US black)

1. unpleasant.

[US](con. 1920s–30s) J.O. Killens Youngblood (1956) 415: Youngblood just don’t like this bad-ass whiskey you sell.
[US](con. 1958) R. Farina Been Down So Long (1972) 73: Oh bad-ass scene. Get them out of here.

2. (also ass-bad, bad-arse, bad-assed) tough, aggressive, frightening.

[US]J. Blake letter 28 Dec. in Joint (1972) 75: Remember Sandy, the sullen kid [...] Wanted to be a hard-nosed badass type.
[US]R. Abrahams Deep Down In The Jungle 54: Now the lion came through the jungle one peaceful day, / When the signifying monkey stopped him, and that is what he started to say: / He said, ‘Mr Lion,’ he said, ‘A bad-assed motherfucker down your way.’ 79: I’m that bad-ass so-and-so they call ‘Stackolee’.
[US]B. Jackson Get Your Ass in the Water (1974) 179: There’s gonna be some badassed happenings if I don’t get invited.
[US]S. Ace Stand On It (1979) 249: They stage a few bad-ass, no-account races for trophies.
[US]R.R. Moore ‘Signifyin’ Monkey’ [lyrics] Way down in the jungle deep, / The bad ass lion stepped on the signifyin monkey’s feet.
[US]L. Stringer Grand Central Winter (1999) 67: It was better to go inside with a ‘don’t-give-a-fuck’ badass rep preceding him.
[UK]Guardian Rev. 15 Oct. 17: If that means pretending to be a badass rock chick, so be it.
[US]J. Stahl Plainclothes Naked (2002) 306: What kind of person’s so ass-bad they don’t even lock their door?
[NZ]A. Duff Jake’s Long Shadow 227: It takes so many down with it [...] li’l Monty grown into a big bad-arse bastard.
[US]J. Lerner You Got Nothing Coming 14: Greasy, matted shoulder-length hair (secured by filthy rubber bands) and five identical goatees scraggily aspiring to a bad-ass look.
[UK]L. Theroux Call of the Weird (2006) 180: Jeezy looked [...] thrillingly badass.
[US]Codella and Bennett Alphaville (2011) 362: Even tough-talking, badass Animal eventually decided to cooperate.
[US]D. Winslow The Force [ebook] The badass look helps him stay out of the physical confrontations.

3. of people, animals, objects: formidable, admirable, first-rate.

[US]M. Van Peebles [film title] Sweet Sweetback’s Baadasssss Song.
[US]V.E. Smith Jones Men 7: She was dressed all in white with a bad-ass mink round her shoulders.
[US]J.L. Gwaltney Drylongso 232: God is the baddest ass in the firmament! He spare who he want to and He strike who he want to.
[US]L. Stavsky et al. A2Z.
[US](con. 1986) G. Pelecanos Sweet Forever 5: A bad-ass prison picture called Short Eyes.
[US]G. Pelecanos Right As Rain 214: Logan had this dog, a boxer mix, called him Greco. Bad-ass dog, too [...] and I always liked the name.
[US]G. Tate Midnight Lightning 111: Ahmad’s crew were mostly his cousins [...] They were ‘fine,’ bad-ass football players.
[UK]Eve. Standard 20 Apr. 14/2: She is suddenly not only very popular but has also acquired a completely surprising badass cool.

In compounds