- any animal as distinguished from a human being: neither man nor beast
- any large, four-footed animal; sometimes, specif., a domesticated animal
- qualities or impulses like an animal's: to bring out the beast in him
- a person who is gross, brutal, vile, etc.
Origin of beastMiddle English and Old French beste from Classical Latin bestia from uncertain or unknown; perhaps Indo-European base an unverified form dheus- from source deer