pureblood vs fauna

pureblood and fauna both are nouns.

Word	Noun	Adjective	Verb	Adverb
pureblood	Yes	Yes	No	No
fauna	Yes	No	No	No

As nouns, fauna is a hypernym of pureblood; that is, fauna is a word with a broader meaning than pureblood:

Other hypernyms of pureblood include animal, animate being, beast, brute, creature.

pureblood (noun)	fauna (noun)
a pedigreed animal of unmixed lineage; used especially of horses	a living organism characterized by voluntary movement
	all the animal life in a particular region or period

pureblood (adjective)	fauna (adjective)
having a list of ancestors as proof of being a purebred animal