Shirt
Part of speech: noun
Definition: An article of clothing that is worn on the upper part of the body, and often has sleeves, either long or short, that cover the arms. In "shirts and skins" games, a member of the shirt-wearing team.
Sweater
Part of speech: noun
Definition: A knitted jacket or jersey, usually of thick wool, worn by athletes before or after exercise.A similar garment worn for warmth.A person who sweats.