Green’s Dictionary of Slang

1. (also b.a.) naked; also fig. use; also as adv and phr. in one’s bare ass, unarmed.

c.1930		(ref. to late 19C) N. Kimball Amer. Madam (1981) 92: When I came to, Frenchy, bare-assed as a jaybird, was pouring brandy down my throat.
1933		J.T. Farrell ‘The Little Blond Fellow’ in Short Stories (1937) 70: How’d you like to come in on one of our B. A. parties? [...] everybody parks his underwear at the doo.
1935		S. Kingsley Dead End Act I: philip: Besides, I haven’t got my suit. tommy: Well, go in bareass.
1948		(con. 1944) N. Mailer Naked and Dead 201: They she was bare-ass naked.
1955		R. Bissell High Water 90: I didn’t care if anybody else was around with me standing there bare ass in front of the galley stove.
1957		C. Himes Imabelle 89: ‘God damn it. We can’t go in our bare asses.’ He raised the mattress of the couch and took out a big blued-steel Colt's .45.
1958		A. King Mine Enemy Grows Older (1959) 28: I run myself bare-assed keeping those hounds in trim.
1962		(con. 1940s) G. Mandel Wax Boom 110: That Kraut caught you bare-assed.
1962		E. Stephens Blow Negative! 282: Right in the broad bare-ass daylight.
1965		Guild Dict. Homosexual Terms 3: b.a. (adj., adv.): Bare-assed.
1966		R.H. Rimmer Harrad Experiment 207: Tell ’em to come on in and swim bare-ass.
1967		M. Braly On the Yard (2002) 7: You’re making me horny again parading around pract’ly bare-assed.
1968		N. Heard Howard Street 15: The other whores would ridicule her [...] if she let a trick run her bare-assed out into the night.
1972		R.A. Wilson Playboy’s Book of Forbidden Words 23: To swim B.A. means to swim nude; a simple abbreviation of bare-assed.
1975		E. Torres Carlito’s Way 22: Me and Earl runnin’ around outside bare-ass in the cold.
1986		R. Campbell In La-La Land We Trust (1999) 4: Actresses of considerable fame pranced around on stilletto heels wearing nothing but horsehair tails belted to their rumps and men of wealth and power rode them bare-assed.
1986		S. King It (1987) 670: We’ll [...] strip him bareass and throw his clothes down into the Barrens.
1988		D. Woodrell Muscle for the Wing 38: The dawn came on [...] to find Emil Jadick sitting bare-assed on the back porch.
1989		H. Rawson Dict. of Invective (1991) 26: bare-ass. Naked, sometimes abbreviated to B.A. by kids when they go skinny-dipping.
1990		R. Campbell Sweet La-La Land (1999) 181: Witchcraft ain’t illegal. Just a lot of screwballs jumping bare-assed over swords and fire, kissing the master’s bunghole.
1991		W.T. Vollmann Whores for Gloria 138: There were about twenty people in there, cooks and all – right bare-ass from my eyes!
2000		C. Cook Robbers (2001) 130: Standing bareassed in the room with the towel around his neck.

2. pertaining to striptease, sex.

1992

B. Gifford Night People 61: ‘Have Some Tits with Your Grits.’ Advert for a bare-ass place for truckers.

3. in fig. use, naïve [the image is of a bare-bottomed infant].

1960

C. Cooper Jr Scene (1996) 106: All you bare-assed college boys come out here [...] and think you know it all!

4. (US) minimal, least.

1962		T. Berger Reinhart in Love (1963) 122: I ain’t got a brown bare-ass penny I can call my own.
2014		D.B. Flowers Bangs 303: ‘If Doherty shot you, I’d have gone to his house and broke his jaw, bare-ass minimum!’.

5. (US Und.) of a burglar, not wearing any gloves (to prevent identification).

1973

G.V. Higgins Digger’s Game (1981) 2: No gloves. I heard that about you. The Digger goes in bare-ass.