Antagonist is that opposite person or one thing opposed to another being defined in its general meaning as a contradiction.
Antagonist is in literature the opposite of the protagonist, that is, that character who opposes the protagonist in the development of a conflict in a literary work or film.
Antagonist comes from the Greek antagonism that is composed of the anti- suffix that refers to something opposite and agon or agonistis that means combat, fight, fighter or player.
The word antagonist is related to antagonistic which means something contrary. The antagonist synonyms are: rival, opposition, alter-ego, opposite, opponent. Its antonyms are friend, ally, family.
Antagonist used as an adjective means a struggle against the action of something opposite.
Protagonist and antagonist
In the literary world, specifically in narratology, the antagonist is the one who accompanies the protagonist in the main conflict of the narrative contrary to him. Generally it is the one that increases the confusion or the problem of the protagonist in the work of fiction.
An antagonist is that drug that creates an antagonism by binding to the receptor without activating it. Antagonists block receptor activation generated by agonists.
The antagonist totally or partially cancels the agonist’s action. The relationship between them can be competitive or non-competitive.