털이나 머리카락이 있고 암컷이 새끼에게 젖을 먹여 기르며 대개 새끼를 낳는 온혈 척추동물.
A warm-blooded vertebrate animal of a class that is distinguished by the possession of hair or fur, the secretion of milk by females for the nourishment of the young, and typically the birth of live young.
예문:
"Whales are a type of marine mammal that must surface to breathe air."
"The platypus is a unique mammal because it lays eggs instead of giving birth to live young."
"Humans are classified as mammals because of their biological characteristics."