American spelling vs opsonization

American spelling and opsonization both are nouns.

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

American spelling (noun)	opsonization (noun)
English orthography used in the United States (characterized by 'analyze', 'center', 'usable')	process whereby opsonins make an invading microorganism more susceptible to phagocytosis