The Collaborative International Dictionary of English v.0.48:

Acrobat \Ac"ro*bat\, n. [F. acrobate, fr. Gr. ? walking on
   tiptoe, climbing aloft; ? high + ? to go.]
   One who practices rope dancing, high vaulting, or other
   daring gymnastic feats.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

25 Moby Thesaurus words for "acrobat":
   aerialist, bareback rider, circus artist, clown, contortionist,
   equestrian director, equilibrist, flier, funambulist, gymnast,
   high wire artist, high-wire artist, juggler, lion tamer,
   palaestrian, pancratiast, ringmaster, ropewalker,
   slack-rope artist, snake charmer, sword swallower,
   tightrope walker, trapeze artist, tumbler, weightlifter