American spelling vs premature labor

American spelling and premature labor both are nouns.

Word	Noun	Adjective	Verb	Adverb
American spelling	Yes	No	No	No
premature labor	Yes	No	No	No

American spelling (noun)	premature labor (noun)
English orthography used in the United States (characterized by 'analyze', 'center', 'usable')	labor beginning prior to the 37th week of gestation