means A close-fitting knitted garment for the upper body, or the soft stretchy knit fabric it's made from — now especially the shirt worn by a sports team, often bearing a player's number.

from Named for the island of Jersey in the English Channel, long famous for its knitting industry, where workers turned out warm woolen sweaters for fishermen and sailors. The island's name traces back through Norman French, and the garment's fame spread until 'jersey' came to mean both the knit and the fabric itself. From there it slipped onto the backs of athletes, where the humble fisherman's pullover became a canvas for team colors and immortal numbers.