[mam-uh
l] 
| any vertebrate of the class Mammalia, having the body more or less covered with hair, nourishing the young with milk from the mammary glands, and, with the exception of the egg-laying monotremes, giving birth to live young. |
| mam·mal (mām'əl) n. Any of various warm-blooded vertebrate animals of the class Mammalia, including humans, characterized by a covering of hair on the skin and, in the female, milk-producing mammary glands for nourishing the young. [From Late Latin mammālis, of the breast, from Latin mamma, breast; see mā-2 in Indo-European roots.] mam·ma'li·an (mā-mā'lē-ən) adj. & n. |
A class of vertebrates characterized by the production of milk by the females and in most cases, by a hairy body covering. Most mammals give live birth to their young. Human beings are mammals.