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

Example Sentences

Leavitt also leaned into her favorite antagonist — the press.

From Salon • Mar. 6, 2026

The Prime Video series premiering Wednesday reimagines the fictional detective’s early years as he investigates a murder case that originates at Oxford, where he first meets his eventual antagonist.

From Los Angeles Times • Mar. 4, 2026

As in normal years, worshippers booed and waved noisemakers each time the story's antagonist, Haman, was announced, before drinking and dancing to pop music despite the unusual setting.

From Barron's • Mar. 2, 2026

He’s spent the last few months acting as his primary antagonist, using his same language and temperament to make fun of him, all while promising Californians something better.

From Slate • Feb. 25, 2026

He liked that there was a new protagonist in the same world and that the previous protagonist was now the antagonist.

From "Healer of the Water Monster" by Brian Young

Related Words

• adversary
• enemy
• foe