sweater

A sweater is a warm knitted top for cold days. Wool, long sleeves, pulled on over your head.

Americans say sweater where the British say jumper, and both are utterly ordinary in their own country. Pullover works everywhere. The name comes from the garments once worn to make athletes sweat off weight, which is a grim origin for something so cosy. A sweatshirt is the cotton version, and a sweater dress is the long one. Britain also has the jumper's dangerous cousin, the Christmas jumper.