sweater [sweaters](knitted jacket worn by athletes before or after exercise) noun [UK: ˈswe.tə(r)] [US: ˈswe.tər]
sweatshirt [sweatshirts](loose shirt, usually made of a knit fleece, for athletic wear and now often used as casual apparel) noun [UK: ˈswe.tʃɜːt] [US: ˈswe.ˌtʃərt]