variety vs unvarying

variety is a noun but unvarying is not a noun.

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

variety (noun)	unvarying (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

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