scatology vs dirty word

scatology and dirty word both are nouns.

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

As nouns, dirty word is a hypernym of scatology; that is, dirty word is a word with a broader meaning than scatology:

scatology: a preoccupation with obscenity (especially that dealing with excrement or excretory functions)
dirty word: an offensive or indecent word or phrase

Other hypernyms of scatology include filth, obscenity, smut, vulgarism.

scatology (noun)	dirty word (noun)
(medicine) the chemical analysis of excrement (for medical diagnosis or for paleontological purposes)	an offensive or indecent word or phrase
a preoccupation with obscenity (especially that dealing with excrement or excretory functions)	a word that is considered to be unmentionable