Green’s Dictionary of Slang

(US) a chicken, a fowl; esp. a sick or dying chicken given by a dealer to a begging tramp; thus chicken stew (see cite 1915).

1899		Young Reminiscences 432: Should a soldier inform a civilian that his bunkie was ‘baked by a bull for jumpin’ a gump’ [...] his meaning would be that his tent mate had been arrested by the provost guard for stealing a chicken [HDAS].
1915		H.F. Day Landloper 34: Some hand-out gump and a train to jump.
1915		Morn. Tulsa Dly World (OK) 13 June 19/2: Gump — Chicken stew.
1926		J. Black You Can’t Win (2000) 62: ‘Not so fast, brother, not so fast. I’ve got a gump in my bindle.’ He unrolled his blankets and produced a live chicken, big and fat.
1930		G. Milburn ‘Gila Monster Route’ in Hobo’s Hornbook 159: Not even a house to beg for a lump, / Nor a hen house there to frisk for a gump.
1944		O. Ferguson ‘Vocabulary for Lakes, [etc.]’ AS XIX:2 103: They will tell you in reminiscence that a chicken pilfered from some convenient roost is a gump; that a clothesline ripe for the taking is a gooseberry bush.
1953		W.L. Alderson ‘Carnie Talk’ in AS XXVIII:2 116: gump, n. A chicken.
1964		(con. 1920s–40s) in J.L. Kornbluh Rebel Voices.
1976		M. Braly False Starts 131: He told me chickens were called gumps because they were as chinless as Andy Gump in the Sunday funnies.
1981		N. Algren ‘Walk Pretty All the Way’ in Entrapment (2009) 271: ‘What in God’s name is a gump, for God’s sake, outside of being something that smells like a dying chicken?’ ‘A gump ain’t nothin’ outside of bein’ a dying chicken, honey. A gump is a dying chicken’.