struggle vs duel

struggle and duel both are nouns.

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

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

Other hyponyms of struggle include scramble, scuffle, joust, tilt.

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

struggle (noun)	duel (noun)
strenuous effort	a prearranged fight with deadly weapons by two people (accompanied by seconds) in order to settle a quarrel over a point of honor
an energetic attempt to achieve something	any struggle between two skillful opponents (individuals or groups)
an open clash between two opposing groups (or individuals)

struggle (verb)	duel (verb)
be engaged in a fight; carry on a fight	fight a duel, as over one's honor or a woman
to exert strenuous effort against opposition
climb awkwardly, as if by scrambling
make a strenuous or labored effort