Green’s Dictionary of Slang

absurd, stupid, with undertones of unpleasantness.

1973		J.B. Rubinstein City Police 427: You know why that dumb-fuck sergeant has Smith drive him?
1979		D. Gram Foxes (1980) 33: Hey, bus! Dumb bus, dumb fucker bus!
1985		(con. 1969–70) D. Bodey F.N.G. (1988) 4: Oh, Jesus. A bunch o’ dumb-fucker clodhoppers.
1987		(con. 1967) Bunch & Cole Reckoning for Kings (1989) 135: Of all the dumb-fuck things to do.
1998		K. Sampson Awaydays 85: I’m just looking at his combat kecks and the dumb-fuck string of spittle dangling from his top lip.
2004		G. Mulholland This Is Uncool 40: The arse-end of British punk that developed from dumb-fuck misanthropy.
2009		(con. 1960s) J. Ellroy Blood’s a Rover 33: Dumb-fuck Hoosiers dug the kaptioned kartoon texts.
2010		L. Berney Gutshot Straight [ebook] Jasper asked what Mr. Moby would generally consider dumb-fuck questions.