fraudster (n.)

mid-14c., "criminal deception" (mid-13c. in Anglo-Latin); from Old French fraude "deception, fraud" (13c.), from Latin fraudem (nominative fraus) "a cheating, deceit," of persons "a cheater, deceiver," of uncertain origin. Connections have been proposed to Sanskrit dhruti- "deception; error."

Meaning "a fraudulent production, something intended to deceive" is from 1650s. The meaning "impostor, deceiver, pretender; humbug" is attested from 1850. Pious fraud (1560s) is properly "deception practiced for the sake of what is deemed a good purpose;" colloquially used as "person who talks piously but is not pious at heart."

Old English -istre, from Proto-Germanic *-istrijon, feminine agent suffix used as the equivalent of masculine -ere (see -er (1)). Also used in Middle English to form nouns of action (meaning "a person who ...") without regard for gender.

The genderless agent noun use apparently was a broader application of the original feminine suffix, beginning in the north of England, but linguists disagree over whether this indicates female domination of weaving and baking trades, as represented in surnames such as Webster, Baxter, Brewster, etc. (though spinster probably carries an originally female ending).

Also compare whitester "one who bleaches cloth;" kempster (c. 1400; Halliwell has it as kembster) "woman who cleans wool." Chaucer ("Merchant's Tale") has chidester "an angry woman." In Modern English, the suffix has been productive in forming derivative nouns (gamester,roadster, punster, rodster "angler," etc.; the 17c. had scoldster).