The Collaborative International Dictionary of English v.0.48:

cardsharp \card"sharp`\, cardsharper \card"sharp`er\n.
   a professional card player who makes a living by cheating at
   card games.
   [WordNet 1.5]

WordNet (r) 3.0 (2006):

cardsharp
    n 1: a professional card player who makes a living by cheating
         at card games [syn: cardsharp, card sharp,
         cardsharper, card sharper, sharper, sharpie,
         sharpy, card shark]

Moby Thesaurus II by Grady Ward, 1.0:

49 Moby Thesaurus words for "cardsharp":
   adventurer, betting ring, bettor, boneshaker, bunco artist,
   bunco steerer, cardshark, cardsharper, carpetbagger,
   compulsive gambler, con artist, con man, confidence man,
   crap shooter, crimp, gambler, gamester, hazarder, horse coper,
   horse trader, jackleg, land pirate, land shark, land-grabber,
   mortgage shark, pettifogger, petty gambler, piker, pitchman,
   player, plunger, punter, shark, sharp, sharper, sharpie,
   shortchanger, shyster, slicker, speculator, spieler, sport,
   sporting man, sportsman, tinhorn, tipster, tout, venturer,
   wagerer