diarrhea vs American spelling

diarrhea and American spelling both are nouns.

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

diarrhea (noun)	American spelling (noun)
frequent and watery bowel movements; can be a symptom of infection or food poisoning or colitis or a gastrointestinal tumor	English orthography used in the United States (characterized by 'analyze', 'center', 'usable')