necrosis vs myonecrosis

necrosis and myonecrosis both are nouns.

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

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

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

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