A jersey is a piece of clothing, typically a shirt or sweater, that fits fairly close to your body.

Today, when people say jersey, they usually mean an athletic jersey: the numbered shirt that athletes wear to show which team they're on. A basketball player's jersey displays their team colors and number, making it easy for teammates, opponents, and fans to identify them during a game. Professional athletes' jerseys can become so meaningful that fans buy replicas to wear in support of their favorite players.

The word also refers to the soft, stretchy fabric itself. Jersey fabric is what makes T-shirts comfortable: it stretches when you move but returns to its original shape. This fabric shows up in everything from casual shirts to dresses because it's flexible and easy to wear.

In British English, jersey can also mean any pullover sweater or sweatshirt, not just athletic ones. So when a British friend mentions wearing a jersey on a cold day, they might just mean a regular warm shirt, not a sports uniform.