unimportant vs significance

unimportant is not a noun while significance is a noun.

Word	Noun	Adjective	Verb	Adverb
unimportant	No	Yes	No	No
significance	Yes	No	No	No

unimportant (noun)	significance (noun)
	the quality of being significant
	a meaning that is not expressly stated but can be inferred
	the message that is intended or expressed or signified

unimportant (adjective)	significance (adjective)
not important
devoid of importance, meaning, or force