unfamiliarity vs foreign

unfamiliarity is a noun but foreign is not a noun.

Word	Noun	Adjective	Verb	Adverb
unfamiliarity	Yes	No	No	No
foreign	No	Yes	No	No

unfamiliarity (noun)	foreign (noun)
unusualness as a consequence of not being well known

unfamiliarity (adjective)	foreign (adjective)
	relating to or originating in or characteristic of another place or part of the world
	of concern to or concerning the affairs of other nations (other than your own)
	not belonging to that in which it is contained; introduced from an outside source
	not contained in or deriving from the essential nature of something