amortization vs American spelling

amortization and American spelling both are nouns.

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

amortization (noun)	American spelling (noun)
payment of an obligation in a series of installments or transfers	English orthography used in the United States (characterized by 'analyze', 'center', 'usable')
the reduction of the value of an asset by prorating its cost over a period of years