antagonist

noun

an·​tag·​o·​nist an-ˈta-gə-nist How to pronounce antagonist (audio)
Synonyms of antagonist
1
: one that contends with or opposes another : adversary, opponent
political antagonists
2
: an agent of physiological antagonism: such as
a
: a muscle that contracts with and limits the action of an agonist with which it is paired

called also antagonistic muscle

b
: a chemical that acts within the body to reduce the physiological activity of another chemical substance (such as an opiate)
especially : one that opposes the action on the nervous system of a drug or a substance occurring naturally in the body by combining with and blocking its nervous receptor compare agonist sense 2b

Did you know?

On the stage or screen, in a story or a novel, the protagonist is the main character and the antagonist is the opposing one. Pro- and ant- usually mark the good and bad characters, but not always; there may occasionally be an evil protagonist and a good antagonist. In the drama of the real world, it's especially hard to sort out which is which, so we usually speak of both parties to a conflict as antagonists. During a strike, for example, representatives of labor and management become antagonists; they often manage to antagonize each other, and the antagonism often remains after the strike is over.

Synonyms of antagonist

Relevance
See All Synonyms & Antonyms in Thesaurus

Examples of antagonist in a Sentence

They are interested in character first, and in Don, a foul-mouthed psychopath with a hair-trigger temper and buried longings for Gal's wife, they have created a truly scary antagonist. —David Ansen, Newsweek, 18 June 2001
In the 1970s researchers discovered that the actions of estrogen and other hormones can be blocked chemically by drugs called hormone antagonists … —David Plotkin, Atlantic, June 1996
If the new comptroller is a true antagonist of the seamy bond market practices he decried in the campaign, why has he installed as his first deputy the public finance director from the Dinkins administration who was Holtzman's accomplice in each of those deals. —Wayne Barrett, Village Voice, March 1994
As in that film, Kopple not only draws an intimate portrait of the protagonists and antagonists in the strike, but also deftly locates the workers' struggle within a broad context of economic and political forces. —Frank Thompson, Film Comment, January/February 1991
please name the novel's hero and his antagonist his antagonist in the boxing match
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Gómez González had been known as a vociferous antagonist of loggers. — Vann R. Newkirk Ii, The Atlantic, 28 July 2026 Broadly speaking, these kinds of stories — powered by a stop-them-before-they-kill-again clock, making their antagonists out to be finicky geniuses or horror movie monsters instead of opportunistic mediocrities — strike me as a low form of fiction. — Robert Lloyd, Los Angeles Times, 27 July 2026 The driving force behind the film’s antagonist, Seo Young-chul (Koo Kyo-hwan), is his belief that imperfect communication is the source of all tragedy. — Rachael Jung, Variety, 26 July 2026 Sekhmet, the Egyptian goddess of war, turns up in the reveal trailer as a major antagonist. — Brian Mazique, Forbes.com, 25 July 2026 See All Example Sentences for antagonist

Word History

Etymology

see antagonize

First Known Use

1555, in the meaning defined at sense 1

Time Traveler
The first known use of antagonist was in 1555

Rhymes for antagonist

See All Rhymes for antagonist

Browse Nearby Words

antagonism
antagonist
antagonistic
See all Nearby Words

Cite this Entry

“Antagonist.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/antagonist. Accessed 3 Aug. 2026.

Copy Citation

Kids Definition

antagonist

noun
an·​tag·​o·​nist an-ˈtag-ə-nəst How to pronounce antagonist (audio)
: one that opposes another

Medical Definition

antagonist

noun
an·​tag·​o·​nist -nəst How to pronounce antagonist (audio)
: an agent that acts in physiological opposition
contact between a tooth and its antagonist in the opposing jaw
: as
a
: a muscle that contracts with and limits the action of an agonist with which it is paired

called also antagonistic muscle

compare agonist sense 1, synergist sense 2
b
: a chemical that acts within the body to reduce the physiological activity of another chemical substance (as an opiate)
especially : one that opposes the action on the nervous system of a drug or a substance occurring naturally in the body by combining with and blocking its nervous receptor compare agonist sense 2

More from Merriam-Webster on antagonist

Nglish: Translation of antagonist for Spanish Speakers

Britannica.com: Encyclopedia article about antagonist

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

More from Merriam-Webster

Word of the Day

Listen to the pronunciation of mitigate

See Definitions and Examples »

Popular in Grammar & Usage

See More

7 Pairs of Commonly Confused Words

Merriam-Webster’s Great Big List of Words You Love to Hate

Is it 'nerve-racking' or 'nerve-wracking'?

'Sneaked' or 'Snuck': Which is correct?

Why does English have so many silent letters?
See More

Popular in Wordplay

See More

Dutch Treat and French Leave: Eight Place-Based Compounds

14 Phobias You Probably Haven't Heard Of

The Longest Long Words List

How long is a jiffy?

Even More Bird Names that Sound Like Insults (and Sometimes Are)
See More

Popular

See More

7 Pairs of Commonly Confused Words

Dutch Treat and French Leave: Eight Place-Based Compounds

14 Phobias You Probably Haven't Heard Of
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
asap street sign
Figure Out These Acronyms ASAP You don't have to be a NASA engineer to get these...
See All