antagonist vs enemy

antagonist and enemy both are nouns.

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

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

antagonist: someone who offers opposition
enemy: an armed adversary (especially a member of an opposing military force)

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

antagonist (noun)	enemy (noun)
a drug that neutralizes or counteracts the effects of another drug	an opposing military force
a muscle that relaxes while another contracts	any hostile group of people
someone who offers opposition	an armed adversary (especially a member of an opposing military force)
	a personal enemy