unfamiliar vs familiarity

unfamiliar is not a noun while familiarity is a noun.

Word	Noun	Adjective	Verb	Adverb
unfamiliar	No	Yes	No	No
familiarity	Yes	No	No	No

unfamiliar (noun)	familiarity (noun)
	an act of undue intimacy
	usualness by virtue of being familiar or well known
	close or warm friendship
	a casual manner
	personal knowledge or information about someone or something

unfamiliar (adjective)	familiarity (adjective)
not known or well known