purebred vs beast

purebred and beast both are nouns.

Word	Noun	Adjective	Verb	Adverb
purebred	Yes	Yes	No	No
beast	Yes	No	No	No

As nouns, beast is a hypernym of purebred; that is, beast is a word with a broader meaning than purebred:

Other hypernyms of purebred include animal, animate being, brute, creature, fauna.

purebred (noun)	beast (noun)
a pedigreed animal of unmixed lineage; used especially of horses	a living organism characterized by voluntary movement
	a cruelly rapacious person

purebred (adjective)	beast (adjective)
bred for many generations from member of a recognized breed or strain