immunization vs American spelling

immunization and American spelling both are nouns.

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

immunization (noun)	American spelling (noun)
the act of making immune (especially by inoculation)	English orthography used in the United States (characterized by 'analyze', 'center', 'usable')