The Collaborative International Dictionary of English v.0.48:

Thimblerig \Thim"ble*rig`\, n.
   A sleight-of-hand trick played with three small cups, shaped
   like thimbles, and a small ball or little pea.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Thimblerig \Thim"ble*rig`\, v. t. [imp. & p. p. Thimblerigged;
   p. pr. & vb. n. Thimblerigging.]
   To swindle by means of small cups or thimbles, and a pea or
   small ball placed under one of them and quickly shifted to
   another, the victim laying a wager that he knows under which
   cup it is; hence, to cheat by any trick.
   [1913 Webster]

WordNet (r) 3.0 (2006):

thimblerig
    n 1: a swindling sleight-of-hand game; victim guesses which of
         three things a pellet is under [syn: shell game,
         thimblerig]

Moby Thesaurus II by Grady Ward, 1.0:

57 Moby Thesaurus words for "thimblerig":
   beat, beguile of, bilk, boiler room, bucket shop, bunco,
   bunco game, burn, cheat, chisel, chouse, chouse out of, cog,
   cog the dice, con, con game, confidence game, cozen, crib, defraud,
   diddle, do in, do out of, euchre, finagle, flam, fleece, flimflam,
   fob, fudge, goldbrick, gouge, gull, gyp, have, hocus, hocus-pocus,
   mulct, pack the deal, pigeon, practice fraud upon, rook, scam,
   screw, sell gold bricks, shave, shell game, shortchange, skin game,
   stack the cards, stick, sting, swindle, take a dive,
   thimblerigging, throw a fight, victimize