obscenity vs dirty word

obscenity and dirty word both are nouns.

Word	Noun	Adjective	Verb	Adverb
obscenity	Yes	No	No	No
dirty word	Yes	No	No	No

As nouns, obscenity and dirty word are synonyms defined as:

Other synonyms of obscenity include filth, smut, vulgarism.

obscenity (noun)	dirty word (noun)
an obscene act	an offensive or indecent word or phrase
the trait of behaving in an obscene manner	a word that is considered to be unmentionable
an offensive or indecent word or phrase