Emily Dickinson Lexicon

CHARL'A-TAN, n. [Fr. from It. ciarlatano, a quack, from ciarlare, to prate; Sp. charlatan, from charlar, to prate; Port. charlar, id.; L. garrulo, garrio; Gr. γηρυω.]

One who prates much in his own favor, and makes unwarrantable pretensions to skill; a quack; an empire; a mountebank. – Brown. Butler.