A deuce poker term is a common slang name for a number two card. So, deuces mean a pair of twos.
You’ll often hear poker players say this term when referring to this specific card. Knowing this term isn’t particularly important from a tactical perspective, but it will help you feel like a part of the conversation when you understand what it means.
For example, you can hear a player commenting on the past hand, saying something like: “I had pocket deuces, so the deuce on the flop helped me make three-of-a-kind.”