Green’s Dictionary of Slang

an all-purpose insult, a nickname for a stupid person.

1967		(con. 1950s) McAleer & Dickson Unit Pride (1981) 328: ‘Hey, shit-for-brains,’ I called to him.
1976		(con. 1969) C.R. Anderson Grunts 130: We are going to do something, shit-for-brains – we’re gonna shut the fuck up.
1981		Star Trib. (Minneapolis, MN) 3 July 30/2: ‘Hey, poop for brains, is that your bleeping truck??!!’.
1986		C. Hiaasen Tourist Season (1987) 124: Typically the letters would begin: ‘Dear Shit-for-Brains’.
1986		R.G. Barrett Godson 335: ‘Can you drive shit-for-brains back to Sydney’.
1989		(con. 1960) P. Theroux My Secret Hist. (1990) 175: Give me a match, shit-for-brains.
1990		(con. c.1970) G. Hasford Phantom Blooper 234: Hey, I got me a job in Istanbul polishing brass-topped buildings, if that’s all right with you, and even if it’s not all right with you, shit-for-brains.
1991		B. Hamper Rivethead (1992) 146: It was impossible to be close friends with a female [...] without a bunch of dick-for-brains assuming that sex was the only bond.
1993		I. Welsh Trainspotting 167: I love you, shite-for-brains.
1998		R.G. Barrett Goodoo Goodoo 255: Follow me, shit for brains.
1999		T. Hanley Flyboys 79: I do got it, poop-for-brains.
2001		N. Griffiths Sheepshagger 2: Foolish fuckin hope tho when a shite-fer-brains like yerself is in on-a conversation, like.
2001		T. Fontana ‘Blizzard of ’01’ Oz ser. 4 ep. 13 [TV script] You got shit for brains.
2006		M. Karp Rabbit Factory (2007) 141: Those shit-for-brains in Sacramento think you can solve a homicide like on the TV shows.
2011		J.J. DeCeglie Drawing Dead [ebook] I’ve got a degree you know jack. I actually finished it unlike you shit for brains.
2017		T. Pluck Bad Boy Boogie [ebook] [T]here’s shit-for-brains in here serving time for running.
2021		S.A. Crosby Razorblade Tears 216: ‘You wanna kill somebody, kill me. Come on, do it, shit for brains’.