'Mammal' definitions:

Definition of 'mammal'

(from WordNet)
noun
Any warm-blooded vertebrate having the skin more or less covered with hair; young are born alive except for the small subclass of monotremes and nourished with milk [syn: mammal, mammalian]

Definition of 'Mammal'

From: GCIDE
  • Mammal \Mam"mal\, n.; pl. Mammals. [L. mammalis belonging to the breast, fr. mamma the breast or pap: cf. F. mammal.] (Zool.) One of the Mammalia. [1913 Webster]
  • Age of mammals. See under Age, n., 8. [1913 Webster]