keratinization vs American spelling

keratinization and American spelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
keratinization	Yes	No	No	No
American spelling	Yes	No	No	No

keratinization (noun)	American spelling (noun)
organic process by which keratin is deposited in cells and the cells become horny (as in nails and hair)	English orthography used in the United States (characterized by 'analyze', 'center', 'usable')