zoology vs fauna

zoology and fauna both are nouns.

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

As nouns, zoology and fauna are synonyms defined as:

zoology (noun)	fauna (noun)
the branch of biology that studies animals	a living organism characterized by voluntary movement
all the animal life in a particular region or period	all the animal life in a particular region or period