Green’s Dictionary of Slang

a cheat, a (confidence) trickster.

1688		J. Shirley Triumph of Wit 201: The Wheedler’s Business is much in trimming the Sails of Flattery, and forming his speeches and Actions to the Humour and Constitution of the Person he undertakes.
1707		J. Shirley Triumph of Wit (5 edn).
1739		Moliere [trans.] Ouevres 8 87: ’Tis a true Wheedler. [...] He’ll drain you to the last Farthing.
1754		Scoundrel’s Dict. 5: He or She that sets up for a thriving Wheedler, must be no Novice [...] but must first be accomodated with a winning Behaviour, a fluent Tongue, weighty Expression, that can be so cunningly couched, as to make bad seem good, and good bad, to the Eyes and Understanding of the Ignorant.