Mammalia, n. pl. [NL., from L. mammalis. See Mammal.].
The highest class of Vertebrata. The young are nourished for a time by milk, or an analogous fluid, secreted by the mammary glands of the mother. [1913 Webster]
n.pl. A family of vertebrate animals whose females in a
state of nature suckle their young, but when civilized and enlightened
put them out to nurse, or use the bottle.