The Collaborative International Dictionary of English v.0.48:

Mountebank \Mount"e*bank\, v. t.
   To cheat by boasting and false pretenses; to gull. [R.]
   --Shak.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Mountebank \Mount"e*bank\, v. i.
   To play the mountebank.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Mountebank \Mount"e*bank\, n. [It. montimbanco, montambanco;
   montare to mount + in in, upon + banco bench. See Mount,
   and 4th Bank.]
   1. One who mounts a bench or stage in the market or other
      public place, boasts of his skill in curing diseases, and
      vends medicines which he pretends are infallible remedies;
      a quack doctor.
      [1913 Webster]

            Such is the weakness and easy credulity of men, that
            a mountebank . . . is preferred before an able
            physician.                            --Whitlock.
      [1913 Webster]

   2. Any boastful or false pretender; a charlatan; a quack.
      [1913 Webster]

            Nothing so impossible in nature but mountebanks will
            undertake.                            --Arbuthnot.
      [1913 Webster]

WordNet (r) 3.0 (2006):

mountebank
    n 1: a flamboyant deceiver; one who attracts customers with
         tricks or jokes [syn: mountebank, charlatan]

Moby Thesaurus II by Grady Ward, 1.0:

65 Moby Thesaurus words for "mountebank":
   artist, artiste, belly dancer, blagueur, bluff, bluffer,
   burlesque queen, charlatan, cheat, chorine, chorus boy,
   chorus girl, con man, confidence man, conjurer, coryphee, dancer,
   dancing girl, defrauder, ecdysiast, entertainer, exotic dancer,
   fake, faker, female impersonator, flimflammer, fourflusher, fraud,
   geisha, geisha girl, guisard, guiser, gyp, hoofer, humbug,
   impersonator, impostor, magician, malingerer, mummer, musician,
   nautch girl, peeler, performer, phony, poser, poseur,
   prestidigitator, pretender, public entertainer, quack, quacksalver,
   quackster, ringer, saltimbanco, sham, shammer, sharper, show girl,
   singer, stripper, stripteaser, stripteuse, vaudevillian,
   vaudevillist