American spelling vs heat of vaporization

American spelling and heat of vaporization both are nouns.

Word	Noun	Adjective	Verb	Adverb
American spelling	Yes	No	No	No
heat of vaporization	Yes	No	No	No

American spelling (noun)	heat of vaporization (noun)
English orthography used in the United States (characterized by 'analyze', 'center', 'usable')	heat absorbed by a unit mass of a material at its boiling point in order to convert the material into a gas at the same temperature