jersey
A jersey in a sports context refers to a shirt commonly worn as part of a uniform in competitive sports such as American football, basketball, hockey, rugby, and soccer. Jerseys commonly feature a team's colors as well as a print of the name, and associated number of a player. Some jerseys will have the name of the team, or that team's logo printed instead of a player's name.
A jersey in a non-sports context is a knitted garment that resembles a t-shirt. It is uncommon to be able to tell the difference, and modern sports jerseys do not adhere to the tradition of knitting the garments.