1. (雌性动物的)乳头，奶头
A teat is a pointed part on the body of a female animal which her babies suck in order to get milk.
2. (尤指奶瓶上的)塑料(或橡皮)奶嘴
A teat is a piece of rubber or plastic that is shaped like a teat, especially one that is fitted to a bottle so that a baby can drink from it.