Green’s Dictionary of Slang

a cheat, a (confidence) trickster.

1707		J. Shirley Triumph of Wit 178: 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.
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.