Antagonist

Part of speech: noun

Pronunciation: /ænˈtæɡənɪst/

Definitions

1. A person who actively opposes or is hostile to someone or something; a rival or adversary in a conflict
2. An individual who opposes or competes against another in a dispute or contest ; a compound that inhibits or blocks the effect of another in a biological system
3. One who stands against or resists another party in an argument or fight ; a molecule that prevents activation or diminishes a biological response by another substance

Etymology: The Greek "antagonistes" did not start out as a word for a villain. It was built from "anti", meaning "against", and "agonistes", a word for a contestant in the games or a combatant in a court case, which itself came from "agon", a contest or struggle. So an antagonist was, at root, simply the other side of a contest, the rival who would meet you in the arena or the courtroom. The Greeks had a verb, "antagonizesthai", to contend against someone, and the noun followed from it. Latin took the noun over as "antagonista", and English borrowed it from there. Nothing in the word's making implies malice; the sense of an enemy or obstacle came later, as English speakers applied it to any opponent or rival. The word's second meaning comes from a different field. In physiology and pharmacology, an antagonist is a substance that blocks or counteracts another, such as a drug that binds to a receptor and stops a natural chemical from acting on it. This modern scientific use reflects the same idea of standing across from another party, now applied to molecules rather than people.

Synonyms: opponent, adversary, foe, competitor, challenger

Antonyms: protagonist, ally, supporter, friend, partner