gangrene vs myonecrosis

gangrene and myonecrosis both are nouns.

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

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

gangrene: the localized death of living cells (as from infection or the interruption of blood supply)
myonecrosis: localized death of muscle cell fibers

gangrene (noun)	myonecrosis (noun)
the localized death of living cells (as from infection or the interruption of blood supply)	localized death of muscle cell fibers
necrotic tissue; a mortified or gangrenous part or mass

gangrene (verb)	myonecrosis (verb)
undergo necrosis