what is a mammal definition
Full Definition of MAMMAL. : any of a class (Mammalia) of warm-blooded higher vertebrates (as placentals, marsupials, or monotremes) that nourish their young with milk secreted by mammary glands, have the skin usually more or less covered with hair, and include humans.â mamÂ·maÂ·liÂ·an \mÉ-ËmÄ-lÄ-Én, ma-\ adjective or noun. a warm-blooded animal (as a dog, mouse, bear, whale, or human being) with a backbone that feeds its young with milk produced by the mother and has skin usually more or less covered with hair.