noun

1. any of a kingdom (Animalia) of eukaryotes generally characterized by a multicellular body, the ability to move quickly and obtain food, specialized sense organs, and sexual reproduction
2. any such organism other than a human being, esp. a mammal or, often, any four-footed creature
3. a brutish, debased, or inhuman person
4. Informal a person, thing, concept, etc. thought of as a kind or type today's athlete is another animal altogether

Etymology: L, living being < anima, animus, breath, air, life principle, soul < IE base *an(e)-, to breathe, exhale > Gr anemos, Sans anilas, wind, breath, OE antha, excitement, anger

adjective

1. of, like, or derived from animals
2. physical rather than mental or spiritual; specif., sensual, gross, bestial, etc.