American spelling vs fossilize

American spelling is a noun but fossilize is not a noun.

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

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

American spelling (verb)	fossilize (verb)
	convert to a fossil
	become mentally inflexible