antagonist vs duelist

antagonist and duelist both are nouns.

Word	Noun	Adjective	Verb	Adverb
antagonist	Yes	No	No	No
duelist	Yes	No	No	No

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

Other hyponyms of antagonist include dueler, dueller, duellist, enemy, foe, foeman, opposition, Luddite, withstander.

antagonist (noun)	duelist (noun)
a drug that neutralizes or counteracts the effects of another drug	a person who fights duels
a muscle that relaxes while another contracts
someone who offers opposition