Green’s Dictionary of Slang

a cheat.

1671		‘L.B.’ New Academy of Complements 201: All the Town is run mad, / And the Hectors do pad, / Besides the false Dice and the Slur-boys: / The new formed Cheats.
c.1698		B.E. Dict. Canting Crew n.p.: Slur a Cheat at Dice.
1725		New Canting Dict. [as cit. c.1698].
1759, 1760, 1776		Bailey Universal Etym. Eng. Dict.