Definitions
1.nounIn scientific usage, a multicellular organism that is usually mobile, whose cells are not encased in a rigid cell wall (distinguishing it from plants and fungi) and which derives energy solely from the consumption of other organisms (distinguishing it from plants)."A cat is an animal, not a plant. Humans are also animals, under the scientific definition, as we are not plants."
2.nounIn non-scientific usage, any member of the kingdom Animalia other than a human.
3.nounIn non-scientific usage, any land-living vertebrate (i.e. not fishes, insects, etc.).
4.nounA person who behaves wildly; a bestial, brutal, brutish, cruel, or inhuman person."My students are animals."
5.nounA person of a particular type."He's a political animal."
6.nounMatter, thing."a whole different animal"