adversary

American  

[ad-ver-ser-ee] / ˈæd vərˌsɛr i /

noun

adversaries plural

1. a person, group, or force that opposes or attacks; opponent; enemy; foe.

   Antonyms:

   ally

2. a person, group, etc., that is an opponent in a contest; contestant.

3. the Adversary, the devil; Satan.

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adjective

1. of or relating to an adversary.

2. involving adversaries, as plaintiff and defendant in a legal proceeding.

   an adversary trial.

adversary British  

/ ˈædvəsərɪ /

noun

1. a person or group that is hostile to someone; enemy

2. an opposing contestant in a game or sport

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adjective

1. the US term for adversarial

Synonym Usage

Adversary, antagonist mean a person or a group contending against another. Adversary suggests an enemy who fights determinedly, continuously, and relentlessly: a formidable adversary. Antagonist suggests one who, in hostile spirit, opposes another, often in a particular contest or struggle: a duel with an antagonist.

Other Word Forms

Derived Forms

• nonadversarial
  adjective
• adversariness
  noun

Inflected Forms

noun

• adversaries
  plural

Etymology

Origin of adversary

First recorded in 1300–50; Middle English adversarie, from Latin adversārius; equivalent to adverse + -ary; replacing Middle English adversere, from Anglo-French

Explanation

An adversary is an enemy or someone who opposes someone else. In tennis, you stand across the net from your adversary. Adversary is related to the word adverse, meaning "against or contrary" — so think of an adversary as someone whom you are fighting against. If you're the undefeated chess champion, you have bested every single one of your adversaries. Adversary is derived from a Latin word meaning "against."

Example Sentences

The main rule of presidential summitry with an adversary is first do no harm.

From The Wall Street Journal • May 15, 2026

"But that's not enough when the adversary is fighting what they see as an existential conflict."

From Barron's • May 11, 2026

One of President Donald Trump's favorite metaphors is that he's got the cards -- that through the might of the United States and his own acumen he can overpower any adversary.

From Barron's • May 11, 2026

"No adversary should mistake our current restraint with a lack of resolve," said Caine, who spoke alongside Hegseth.

From Barron's • May 5, 2026

The cat uttered another banshee scream and stepped forward with a stiff-legged, sideways movement, his squinting, terrible eyes fixed on his enormous adversary.

From "The Incredible Journey" by Sheila Burnford

Related Words

• antagonist
• attacker
• competitor
• enemy
• foe
• opponent
• rival