obscenity vs dirtiness

obscenity and dirtiness both are nouns.

Word	Noun	Adjective	Verb	Adverb
obscenity	Yes	No	No	No
dirtiness	Yes	No	No	No

As nouns, dirtiness is a hyponym of obscenity; that is, dirtiness is a word with a more specific, narrower meaning than obscenity:

Other hyponyms of obscenity include smuttiness.

obscenity (noun)	dirtiness (noun)
an obscene act	obscenity in speech or writing
the trait of behaving in an obscene manner	the state of being unsanitary
an offensive or indecent word or phrase	the state of containing dirty impurities