gangrene vs pathology

gangrene and pathology both are nouns.

Word	Noun	Adjective	Verb	Adverb
gangrene	Yes	No	Yes	No
pathology	Yes	No	No	No

As nouns, pathology is a hypernym of gangrene; that is, pathology is a word with a broader meaning than gangrene:

gangrene (noun)	pathology (noun)
the localized death of living cells (as from infection or the interruption of blood supply)	the branch of medical science that studies the causes and nature and effects of diseases
necrotic tissue; a mortified or gangrenous part or mass	any deviation from a healthy or normal condition

gangrene (verb)	pathology (verb)
undergo necrosis