casualness vs familiarity

casualness and familiarity both are nouns.

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

As nouns, casualness and familiarity are synonyms defined as:

casualness (noun)	familiarity (noun)
a casual manner	an act of undue intimacy
The state of coming without regularity; of being occasional or incidental.	usualness by virtue of being familiar or well known
	close or warm friendship
	a casual manner
	personal knowledge or information about someone or something