American spelling vs endeavor

American spelling and endeavor both are nouns.

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

American spelling (noun)	endeavor (noun)
English orthography used in the United States (characterized by 'analyze', 'center', 'usable')	earnest and conscientious activity intended to do or accomplish something
	a purposeful or industrious undertaking (especially one that requires effort or boldness)

American spelling (verb)	endeavor (verb)
	attempt by employing effort