Green’s Dictionary of Slang

a confidence trickster.

1849		Dublin Eve. Mail 19 Mar. 3/2: Caution to the Public — A Fleecer [...] citizens to be on their guard against one of the most accomplished and successful swindlers.
1891		Coventry Eve. Teleg. 21 Feb. 3/4: An Impudent Swindle [...] Another able fleecer [...] appears on the horizon, or rather disappears — for the individual [...] has departed [...] taking with him a pocket-book well stuffed with bank notes.
1921		Mencken letter 15 Dec. in Riggio Dreiser-Mencken Letters II (1986) 422: Fleecer!
1972		P. Fordham Inside the Und. 65: Both fleecer and fleeced being in prison.
2000		Guardian Rev. 15 Jan. 11: He embarks on a career as [...] a con man, a fleecer of the wealthiest and best-connected women in Britain.