The Collaborative International Dictionary of English v.0.48:

Juggler \Jug"gler\, n. [OE. jogelour, juglur, OF. jogleor,
   jugleor, jongleor, F. jongleur, fr. L. joculator a jester,
   joker, fr. joculus a little jest or joke, dim. of jocus jest,
   joke. See Joke, and cf. Jongleur, Joculator.]
   [1913 Webster]
   1. One who juggles; one who practices or exhibits tricks by
      sleight of hand; one skilled in legerdemain; a conjurer.
      [Archaic]

   Note: This sense is now expressed by magician or
         conjurer.
         [1913 Webster +PJC]

               As nimble jugglers that deceive the eye. --Shak.
         [1913 Webster]

               Jugglers and impostors do daily delude them.
                                                  --Sir T.
                                                  Browne.
         [1913 Webster]

   2. A deceiver; a cheat. --Shak.
      [1913 Webster]

   3. A person who juggles objects, i. e. who maintains several
      objects in the air by passing them in turn from one hand
      to another.
      [PJC]

WordNet (r) 3.0 (2006):

juggler
    n 1: a performer who juggles objects and performs tricks of
         manual dexterity

Moby Thesaurus II by Grady Ward, 1.0:

39 Moby Thesaurus words for "juggler":
   acrobat, aerialist, bareback rider, blackleg, cheat, cheater,
   chiseler, circus artist, clown, conjurer, cozener, crook,
   defrauder, diddler, equestrian director, equilibrist, escamoteur,
   flier, flimflam man, flimflammer, gyp artist, gypper,
   high-wire artist, illusionist, lion tamer, magician,
   prestidigitator, ringmaster, slack-rope artist,
   sleight-of-hand performer, snake charmer, swindler,
   sword swallower, tightrope walker, trapeze artist, tricker,
   trickster, tumbler, two-timer