duel vs battle

duel and battle both are nouns.

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

As nouns, battle is a hypernym of duel; that is, battle is a word with a broader meaning than duel:

Other hypernyms of duel include struggle.

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

duel (verb)	battle (verb)
fight a duel, as over one's honor or a woman	battle or contend against in or as if in a battle