Green’s Dictionary of Slang

1. (orig. US, also dumb-butt) a fool.

1958		J. David College Vocab. 7: Dumb-ass – One who acts stupid.
1962		(con. WWII) J. Jones Thin Red Line (1963) 388: I don’t know what these dumbasses would do if they didn’t have me around to take care of them.
1972		D. Jenkins Semi-Tough 4: Nobody can help being what he is, whether it turns out to be black as a cup of coffee at a truck stop, or a white Southern dumb-ass.
1984		D. Jenkins Life Its Ownself (1985) 191: Some dumbass missed a block or dropped a pass.
1990		W.D. Myers Mouse Rap 52: [O]ld dumb-butt Leroy talked about how I was going to mess Bobby up.
1997		J. Birmingham Tasmanian Babes Fiasco (1998) 159: You’re supposed to say ‘check’, dumb arse!
1997		(con. 1970s) G. Pelecanos King Suckerman (1998) 217: Why’s a smart guy like you working for a dumb-ass like Eddie?
2000		Willowall ‘Amanda Gets Zipped’ 🌐 Do you really think I’m gonna save you from this you fucking dumb-ass?!
2004		K. Bruen ‘Fade To . . . Brooklyn’ in Brooklyn Noir 308: I’m no dumbass, I’ve learned a lot of stuff.
2008		G. Pelecanos Way Home (2009) 204: Dumbass had his share of the money in the trunk of the car.
2010		Big Issue (SA) 5-26 Feb. 11/2: Instructions not be be seen using the map in public like a dumbass.
2011		S. Kelman Pigeon English 21: Criminal leads, dumb-arse.
2013		Izikhotane News (S. Afr.) 12 Mar. 🌐 Dumb ass is da one who fails tah provide ur needs.
2013		J. Stahl Happy Mutant Baby Pills 114: Harold also swore he didn’t mind the ‘dumbasses’ and ‘morons’ they yelled after him.
2018		‘Aidan Truhen’ Price You Pay 85: Ooo but Jack no we bombed those fuckers in their caves and they are all gooooone! Are they dumbass? Are they really?
2024		C. Stella Joey Piss Pot 3: That dumbass was a professor before he cheated on my sister.

2. stupidity.

1972		D. Jenkins Semi-Tough 10: ‘I’m what a lot of you spooks might think of as a red neck with a terminal case of the dumb-ass’.
2012		K. Powers Yellow Birds 193: Sergeant Sterling [...] said, ‘Someone had a big old bowl of dumbass today. Get your shit together’.