diagonalization vs American spelling

diagonalization and American spelling both are nouns.

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

diagonalization (noun)	American spelling (noun)
changing a square matrix to diagonal form (with all non-zero elements on the principal diagonal)	English orthography used in the United States (characterized by 'analyze', 'center', 'usable')