endeavor vs struggle

endeavor and struggle both are nouns.

Word	Noun	Adjective	Verb	Adverb
endeavor	Yes	No	Yes	No
struggle	Yes	No	Yes	No

As nouns, struggle is a hyponym of endeavor; that is, struggle is a word with a more specific, narrower meaning than endeavor:

endeavor: earnest and conscientious activity intended to do or accomplish something
struggle: an energetic attempt to achieve something

As verbs, struggle is a hyponym of endeavor; that is, struggle is a word with a more specific, narrower meaning than endeavor:

Other hyponyms of endeavor include be at pains, take pains, buck.

endeavor (noun)	struggle (noun)
earnest and conscientious activity intended to do or accomplish something	strenuous effort
a purposeful or industrious undertaking (especially one that requires effort or boldness)	an energetic attempt to achieve something
	an open clash between two opposing groups (or individuals)

endeavor (verb)	struggle (verb)
attempt by employing effort	be engaged in a fight; carry on a fight
	to exert strenuous effort against opposition
	climb awkwardly, as if by scrambling
	make a strenuous or labored effort