Mammalia n. pl. : 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.

Example:
What is the Latin or Greek Meaning for Mammalia?

Taxonomy
mammals, Clade, mammalian, Infraclass, monotremes, marsupials, bones, placentals, therapsids, limbs, placental mammals, synapsids, lung, reptiles, fossils, mammal species, animals, Subclass.

Defination from the web:
Mammalia) are a class of vertebrate animals whose females are characterized by the possession of mammary glands while both ... Phylogenetically, Mammalia is defined as all descendants of the most recent common ancestor of monotremes (e.g., echidnas and platypuses) and ...