American spelling vs keratinization

American spelling and keratinization both are nouns.

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

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