unimportance vs obscurity

unimportance and obscurity both are nouns.

Word	Noun	Adjective	Verb	Adverb
unimportance	Yes	No	No	No
obscurity	Yes	No	No	No

As nouns, obscurity is a hypernym of unimportance; that is, obscurity is a word with a broader meaning than unimportance:

unimportance (noun)	obscurity (noun)
the quality of not being important or worthy of note	the quality of being unclear or abstruse and hard to understand
the state of being humble and unimportant	an obscure and unimportant standing; not well known
	the state of being indistinct or indefinite for lack of adequate illumination