Green’s Dictionary of Slang

1. (US) to bully, to behave like a thug; thus, as a n., the act of so doing; thus bad-assery, braggaodcio, arrogance.

1977		L. Heinemann Close Quarters (1987) 130: Quinn and Dewey and I [...] bad-assed our way from Dau Tieng to Tay Ninh and back for many a day.
1996		N. Sayre Sixties Going On Seventies 205: The San Francisco Diggers encouraged people to exchange free LSD, and liked ‘bad-assing the illegal drug trade.’ .
2000		F. Kellerman Stalker (2001) 379: The guy could have had a real bad ass with a Magnum .44. He could have popped you.
2010		IOL News (Western Cape) 22 Oct. 🌐 Rodriguez has offered us many morable characters dripping with bad-assery.

2. in fig. use.

2001

J. Haddam Skeleton Key 142: She [...] saw it [i.e. an automobile] coming, bad-assing down Sixty-three, going really fast.