a flamboyant deceiver; one who attracts customers with tricks or jokes
A mountebank, someone who addresses crowds in the street; (especially), an itinerant seller of medicines or drugs.
The word charlatan comes from the Old Italian ciarlatano, which originally meant "quack." It is a blend of words meaning "chatterer" and "hawker," with the latter part referring to a native of Cerreto di Spoleto, a village in Umbria known for its quacks.