unregistered vs fauna

unregistered is not a noun while fauna is a noun.

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

unregistered (noun)	fauna (noun)
	a living organism characterized by voluntary movement
	all the animal life in a particular region or period

unregistered (adjective)	fauna (adjective)
not registered
(of animals) not recorded with or certified by an official breed association
(a boat or vessel) not furnished with official documents