card counter: Meaning and Definition of

card' count"er

Pronunciation: [key]
— Blackjack.
  1. a casino player who memorizes or records which cards have been played in previous hands in order to calculate the odds on receiving winning cards or combinations from those remaining to be dealt, the practice often being held as illegal.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.