myelinization vs ontogeny

myelinization and ontogeny both are nouns.

Word	Noun	Adjective	Verb	Adverb
myelinization	Yes	No	No	No
ontogeny	Yes	No	No	No

As nouns, ontogeny is a hypernym of myelinization; that is, ontogeny is a word with a broader meaning than myelinization:

myelinization: the development of a myelin sheath around a nerve fiber
ontogeny: (biology) the process of an individual organism growing organically; a purely biological unfolding of events involved in an organism changing gradually from a simple to a more complex level

Other hypernyms of myelinization include development, growing, growth, maturation, ontogenesis.

myelinization (noun)	ontogeny (noun)
the development of a myelin sheath around a nerve fiber	(biology) the process of an individual organism growing organically; a purely biological unfolding of events involved in an organism changing gradually from a simple to a more complex level