Real Dictionary

mammal
a person who receives or entertains guests, esp in his or her own home [...]
a small simple room, as in a prison, convent, or monastery; cubicle [...]
any animal of the Mammalia, a large class of warm-blooded vertebrates having mammary glands in the female, a thoracic diaphragm, and a four-chambered heart. The class includes the whales, carnivores, rodents, bats, primates, etc [...]
any of the taxonomic groups into which a genus is divided, the members of which are capable of interbreeding: often containing subspecies, varieties, or races. A species is designated in italics by the genus name followed by the specific name, for example
the act or an instance of transforming ideas into words [...]
countable noun: Mammals are animals such as humans, dogs, lions, and whales. Most female mammals give birth to babies rather than laying eggs, and all female mammals feed their young with milk.