Trey/treɪ/ Definition 1 of 3Pro Tip 1/3Card and Dice Trey as related to cards or dice is often used in games where distinguishing numbers matters. She needed a trey to win at craps. Pro Tip 2/3Gambling Term In casino settings, 'trey' is common language among players and dealers for quick communication. The dealer called out 'trey' as the dice landed. Pro Tip 3/3Not for Tally Avoid using 'trey' for counting objects or people; it's specific to cards and dice. In the game, finding a trey is more exciting than finding a two.