Deuce is a widely used term that refers to a number two. While it can be used in everyday life, the term is most often used in casinos, and when it comes to gaming establishments, deuce can be used in multiple ways.
For example, if you are playing dice, if someone rolls two 1s, you can say they have rolled either a deuce or a pair of snake eyes.
The term is also used among poker players and refers to a single card with a value of two. Therefore, you may often hear someone saying they have a pair of deuces.