Green’s Dictionary of Slang

as a derog. epithet, describing one who tricks money out of someone; also as n.

1860		Knickerbocker LVI 458: Outside of a kind of twopenny shystering smartness and snap-judgment genius, Dovey was [...] rather a cross between a Dutch dumpling and a one-horse blower [DA].
1872		in R.G. White Amer. View Copyright 40: At Monday’s session an unprepossessing person [...] made a ‘shystering,’ pettifogging speech [DA].
1872		Western Daily Press (Bristol) 1 Apr. 3/6: The government should not allow its reputation to be compromised [...] by any such shystering.
1880		Wlky Commonwealth (Topeka, KS) 26 Aug. 1/2: It is an insult to the people of Kansas [that] these people carry out their shystering practices [...] We denounce political shystering.
1889		Bucks Herald 22 June 10/1: It is so when pretence is only a cover for shystering Pharisees.
1895		Advocate (Topeka, KS) 7 Aug. 8/1: John Waller has a reputation in Kansas of a shystering politician and an all-round deadbeat.
1938		X. Herbert Capricornia (1939) 365: I aint got a chance to win it back with all these jiggerin’ damn dunns and blunny graspin’ shysterin’ barsteds grabbin’ me pay soon’s I blunny well get it.
1974		Algona Upper Des Moines (IA) 13 June 15/2: ‘He suspects that vehicle dealers in Minnesota towns [...] are just a litte shystering’.