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):

cardsharper
    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]