fossilization vs American spelling

fossilization and American spelling both are nouns.

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

fossilization (noun)	American spelling (noun)
becoming inflexible or out of date	English orthography used in the United States (characterized by 'analyze', 'center', 'usable')
the process of fossilizing a plant or animal that existed in some earlier age; the process of being turned to stone