ionization vs American spelling

ionization and American spelling both are nouns.

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

ionization (noun)	American spelling (noun)
the process of ionizing; the formation of ions by separating atoms or molecules or radicals or by adding or subtracting electrons from atoms by strong electric fields in a gas	English orthography used in the United States (characterized by 'analyze', 'center', 'usable')
the condition of being dissociated into ions (as by heat or radiation or chemical reaction or electrical discharge)