antagonist vs foeman

antagonist and foeman both are nouns.

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

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

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

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

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