naturalization vs American spelling

naturalization and American spelling both are nouns.

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

naturalization (noun)	American spelling (noun)
the proceeding whereby a foreigner is granted citizenship	English orthography used in the United States (characterized by 'analyze', 'center', 'usable')
changing the pronunciation of a borrowed word to agree with the borrowers' phonology
the introduction of animals or plants to places where they flourish but are not indigenous
the quality of being brought into conformity with nature