Green’s Dictionary of Slang

1. (US Und., also shunk) a novice criminal.

1914		Jackson & Hellyer Vocab. Criminal Sl. 75: shoniker [...] Current among cosmopolitan thieves, especially Jews. A neophyte or inexperienced hand at the game.
1928		Eve. Teleg (Dundee) 14 Nov. 8/2: I couldn’t rob your house, sweetheart, I’d feel too much of a shunk.

2. a derog. term for a Jew.

1914		implied in sense 1.
1927		‘Jargon of the Und.’ in DN V 462: Shonnicker, A Jewish pawnbroker.
1931		Irwin Amer. Tramp and Und. Sl. 168: Shonnicker. – A Jewish pawnbroker, more especially when also a ‘fence.’.
1932		(con. 1910s) J.T. Farrell Young Lonigan in Studs Lonigan (1936) 114: Barney is a combination of eight ball, mick, and shonnicker.
1934		(con. 1920s) J.T. Farrell Young Manhood in Studs Lonigan (1936) 410: He would have settled those profiteering shonickers.
1942		Berrey & Van den Bark Amer. Thes. Sl.
1949		Monteleone Criminal Sl. (rev. edn) 206: shonnacker [...] shonniker A Jew; a pawnbroker; a receiver of stolen goods.
1961		H.C. Woodbridge ‘Miscellany’ in AS XXXVI:3 228: shonicker, n. Jew.
1962		Ragen & Finston World’s Toughest Prison 817: shonnicker – A Jewish pawnbroker.
1983		I.L. Allen Lang. of Ethnic Conflict 61: Jew [...] schonocker.