sharper

petkuttaja (en-comparative of)
puhekieltä a swindler; a cheat; a professional gambler who makes his living by cheating.
1766, (w), (w), Letter XXIX, http://www.gutenberg.org/files/2311/2311-h/2311-h.htm

Our young gentlemen who go to Rome will do well to be upon their guard against a set of sharpers, (some of them of our own country,) who deal in pictures and antiques, and very often impose upon the uninformed stranger, by selling him trash, as the productions of the most celebrated artists.

(..) in a twinkling the accomplished sharper changes the pitchers and pretending to examine the contents, asks the tapster what kind of wine he has given him (..)

The Derby Day sun glittered gaily on cads, / On maidens with gamboge hair, / On sharpers and pickpockets, swindlers and pads— / (For I, with my harp, was there).