familiar vs familiarity

familiar and familiarity both are nouns.

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

familiar (noun)	familiarity (noun)
a spirit (usually in animal form) that acts as an assistant to a witch or wizard	an act of undue intimacy
a person attached to the household of a high official (as a pope or bishop) who renders service in return for support	usualness by virtue of being familiar or well known
a friend who is frequently in the company of another	close or warm friendship
	a casual manner
	personal knowledge or information about someone or something

familiar (adjective)	familiarity (adjective)
well known or easily recognized
within normal everyday experience; common and ordinary; not strange
having mutual interests or affections; of established friendship
(usually followed by `with') well informed about or knowing thoroughly