Any of various warm-blooded vertebrate animals of the class Mammalia, including human beings, characterized by a covering of hair on the skin and, in the female, milk-producing mammary glands for nourishing the young.

• 哺乳动物任一种包括人类在内的哺乳动物纲的温血脊椎动物，其特点是皮肤上有一层毛，雌性具有养育幼崽的能产生奶汁的乳腺