metaphysis vs outgrowth

metaphysis and outgrowth both are nouns.

Word	Noun	Adjective	Verb	Adverb
metaphysis	Yes	No	No	No
outgrowth	Yes	No	No	No

As nouns, outgrowth is a hypernym of metaphysis; that is, outgrowth is a word with a broader meaning than metaphysis:

metaphysis: the growing part of a long bone between the diaphysis and the epiphysis
outgrowth: a natural prolongation or projection from a part of an organism either animal or plant

Other hypernyms of metaphysis include appendage, process.

metaphysis (noun)	outgrowth (noun)
the growing part of a long bone between the diaphysis and the epiphysis	a natural prolongation or projection from a part of an organism either animal or plant
	the gradual beginning or coming forth
	a natural consequence of development