antagonist vs dueller

antagonist and dueller both are nouns.

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

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

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

antagonist (noun)	dueller (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