diagonalize vs American spelling

diagonalize is not a noun while American spelling is a noun.

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

diagonalize (noun)	American spelling (noun)
	English orthography used in the United States (characterized by 'analyze', 'center', 'usable')

diagonalize (verb)	American spelling (verb)
transform a matrix to a diagonal matrix