unvarying vs variety

unvarying is not a noun while variety is a noun.

Word	Noun	Adjective	Verb	Adverb
unvarying	No	Yes	No	No
variety	Yes	No	No	No

unvarying (noun)	variety (noun)
	noticeable heterogeneity
	a difference that is usually pleasant
	a category of things distinguished by some common characteristic or quality
	a show consisting of a series of short unrelated performances
	(biology) a taxonomic category consisting of members of a species that differ from others of the same species in minor but heritable characteristics
	a collection containing a variety of sorts of things

unvarying (adjective)	variety (adjective)
lacking variety
always the same; showing a single form or character in all occurrences
unvarying in nature