morphology vs accidence

morphology and accidence both are nouns.

Word	Noun	Adjective	Verb	Adverb
morphology	Yes	No	No	No
accidence	Yes	No	No	No

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

Other hyponyms of morphology include inflectional morphology, derivational morphology, compound morphology.

morphology (noun)	accidence (noun)
the branch of biology that deals with the structure of animals and plants	the part of grammar that deals with the inflections of words
studies of the rules for forming admissible words
the admissible arrangement of sounds in words
the branch of geology that studies the characteristics and configuration and evolution of rocks and land forms