Green’s Dictionary of Slang

chump adj.

also chump-ass
[chump n.]

1. stupid, gullible.

implied in chumphead under chump n.
[US]Atlanta Constitution 29 Aug. 42/3: The underworld saw John Burglar metamorphose overnight from a ‘chump copper’ to a precinct captain reputed to be a ‘wise guy’.
[US]Eve. Star (Wash., DC) 14 Mar. 61/2: The chump brother-in-law of Mr Robert.
[US]B. De Beck Barney Google [comic strip] I ain’t gonna get wheeled around in a ‘chump chariot’.
[US](con. 1920s) J.T. Farrell Young Manhood in Studs Lonigan (1936) 379: He wished it was over or that he hadn’t been chump enough to let himself in for such a thing.
[US]V.E. Smith Jones Men 9: That’s how he got over so quick, robbing these little chump people.
[US]‘Master Pimp’ Pimp’s Rap 165: Well, chump-ass nigger, ‘What’s it gonna be, snake eyes or seven eleven?’.

2. unsophisticated, second-rate, provincial.

[US]D. Runyon ‘Undertaker Song’ in Runyon on Broadway (1954) 333: The upshot of thousands of other cases since chump dolls commence coming to Broadway.
[US]‘Iceberg Slim’ Pimp 98: Get out of town and be a good pimp in a chump town.
[US]V.E. Smith Jones Men 6: Joe used to rayfield a chump bag dude too.
[US]J.L. Gwaltney Drylongso 214: I’m not talking about the little five-thousand-dollar chump change-pushers, but I mean the ones that are making the millions.
[US]M. Leyner Et Tu, Babe (1993) 39: No chasing Iron Man Wang and his posse of hot-wired sex freaks around the world. That’s chump shit, man.
[US]J. Lerner You Got Nothing Coming 217: The minute I finish this chump-ass bid in Nevada thy’ll be coming to take me back to finish out my time in the Kansas pen.