Green’s Dictionary of Slang

dumb-ass adj.

also dumb-arse, dumb-assed
[dumb-ass n.]

(orig. US) stupid, unintelligent.

[US]B. Appel Brain Guy (1937) 60: Betting his life on the card of a dumb ass crack.
[US]H. Gold Man Who Was Not With It (1965) 257: Well then you’re nothing but another dumb-ass mark in the crowd.
[US]H. Simmons Corner Boy 198: You’re nothing but a dumb-assed nigger!
[US](con. WWII) J.O. Killens And Then We Heard The Thunder (1964) 29: You too educated for us dumb-ass colored soldiers.
[US]N. Heard Howard Street 176: Some dumb-assed doctors [...] tell the public that a guy can git a habit from smokin’ pot.
[US]T. Southern Blue Movie (1974) 233: How the hell is me getting fucked, on camera, by a bunch of . . . stupid . . . dumb-ass . . . nigger extras going to help my image?
[US](con. 1968) D.A. Dye Citadel (1989) 135: Crying like a dumb-assed baby.
[US]D. Woodrell Muscle for the Wing 74: I’m going to tell you how Bell got his dumb-ass self greased.
[UK]J. Mowry Six Out Seven (1994) 41: My mom wants go an treat some dumb-ass niggerboy like a guest, she gots that right.
[US]J. Ridley Conversation with the Mann 55: That [...] is how you dumb-ass niggers move a bunk.
[Aus]L. Redhead Rubdown [ebook] Occupational hazard when you work with dumb-arse rednecks.
B. Reed ‘Messman on C.E.’s Altar’ in Passing Strange (2015) 22: ‘You’re the stupid fucking idiot fucking cunt who deliberately overturned his dumb-arsed stupid fucking truck’.
[UK]A. Wheatle Dirty South 4: Making me feel as stupid as a dumb-ass ghetto brother faced with quantum physics.
[Aus] J.J. DeCeglie ‘Death Cannot Be Delegated’ in Crime Factory: Hard Labour [ebook] Sore about [...] her dumbarse plan goin to hell.
[US]S. King Finders Keepers (2016) 11: Don’t give me your dumbass literary criticism.
[US]D. Winslow ‘The Last Ride’ in Broken 286: ‘You dumbass cammies and your ARs’.