Green’s Dictionary of Slang

(US) a detestable person.

1935		N. Algren Somebody in Boots 261: Jest a little side-windin’ schtunk, that’s all he ever was.
1935		N. Algren ‘Thundermug’ in Texas Stories (1995) 76: Say, fellers, ain’t it a honor to be Head-Chief-Shtunk, anywhere?
1941		B. Schulberg What Makes Sammy Run? (1992) 111: Listen, shtunk, for Chri’sake who the hell told you to come out here?
1975		Wentworth & Flexner DAS 738: schtoonk n. A contemptible person; ‘stinker’.
1977		E. Torres Q&A 131: With all due respect, he’s a shtonk.
1981		P. Appleman Shame the Devil 33: Schtoonk! Jessie shrieked at him. Schlemiel!
1998		W.W. Johnstone Wind in the Ashes 320: Gettin’ ready to kick the hell out of that schtoonk, Hartline, that’s what.