: a person who opposes another person He faced his antagonist [=(more commonly) opponent, adversary] in a series of debates.

Is antagonist the opponent?

antagonist, in literature, the principal opponent or foil of the main character, who is referred to as the protagonist, in a drama or narrative. The word is from the Greek antagnistḗs, “opponent or rival.”

What is called antagonist?

a person who is opposed to, struggles against, or competes with another; opponent; adversary. the adversary of the hero or protagonist of a drama or other literary work: Iago is the antagonist of Othello. Physiology.