antagonist

American  

[an-tag-uh-nist] / ænˈtæg ə nɪst /

noun

1. a person who is opposed to, struggles against, or competes with another; opponent; adversary.

   Synonyms:

   foe, enemy, contestant

   Antonyms:

   friend, ally

2. the adversary of the hero or protagonist of a drama or other literary work.

   Iago is the antagonist of Othello.

3. Physiology. a muscle that acts in opposition to another.

4. Dentistry. a tooth in one jaw that articulates during mastication or occlusion with a tooth in the opposing jaw.

5. Pharmacology. a drug that counteracts the effects of another drug.

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antagonist British  

/ ænˈtæɡənɪst /

noun

1. an opponent or adversary, as in a contest, drama, sporting event, etc

2. any muscle that opposes the action of another Compare agonist

3. a drug that counteracts the effects of another drug Compare synergist

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antagonist Scientific  

/ ăn-tăg′ə-nĭst /

1. A muscle that opposes the action of another muscle, as by relaxing while the other one contracts, thereby producing smooth, coordinated movement.

2. A chemical substance, such as a drug, that interferes with the physiological action of another substance, especially by combining with and blocking its nerve receptor.

3. Compare agonist

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Related Words

See adversary.

Etymology

Origin of antagonist

First recorded in 1590–1600; from Late Latin antagōnista, from Greek antagōnistḗs. See antagonize, -ist

Explanation

An antagonist is someone who opposes someone else. In Superman comics, the antagonist is Lex Luthor, evil genius and archenemy of the superhero. The noun antagonist shows up a lot when people are talking about books, plays, or movies to mean "the bad guy," but it can also be used to talk about a real person if she acts against someone else. An antagonist is always in opposition, but she isn't always bad or mean; your opponent on the tennis court, for example, could be called your antagonist, simply because it is her priority to beat you in your tennis game.

Example Sentences

Neurocrine already markets Crenessity, an oral CRF1 receptor antagonist used to treat congenital adrenal hyperplasia, which is a collection of genetic disorders affecting the adrenal glands.

From MarketWatch • Apr. 6, 2026

Introducing a surprise antagonist has long been a key ingredient of the WWE recipe, and at this point Brady surfacing is all but expected.

From Los Angeles Times • Mar. 20, 2026

Veteran video game actor Troy Baker is nominated twice - for his lead performance as Indiana Jones in The Great Circle and for his supporting role as antagonist Higgs in Death Stranding 2.

From BBC • Mar. 12, 2026

Leavitt also leaned into her favorite antagonist — the press.

From Salon • Mar. 6, 2026

It was a new chapter with a similar theme and a more intense antagonist.

From "A Deadly Wandering: A Mystery, a Landmark Investigation, and the Astonishing Science of Attention in the Digital Age" by Matt Richtel

Related Words

• adversary
• enemy
• foe