adversarial

adjective

ad·​ver·​sar·​i·​al ˌad-vər-ˈser-ē-əl How to pronounce adversarial (audio)
ˌad-və-
-ˈse-rē-
Synonyms of adversarialnext
: involving two people or two sides who oppose each other : of, relating to, or characteristic of an adversary or adversary procedures (see adversary entry 2 sense 2)
an adversarial relationship
an adversarial system of justice with prosecution and defense opposing each other

Examples of adversarial in a Sentence

an adversarial system of justice with prosecution and defense opposing each other the relationship between the president and the congress should not be adversarial if anything is to get done
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.
His findings reflect the experience of the company’s Frontier Red Team, a group of 15 Anthropic employees tasked with challenging cybersecurity by simulating adversarial attacks. Victor Tangermann, Futurism, 16 Apr. 2026 Spain, the eurozone’s fourth-largest economy, has been less adversarial toward China than other EU countries in recent years. ABC News, 13 Apr. 2026 Jena Griswold, Colorado’s Democratic secretary of state, has come to see the federal government as adversarial to elections and election administration, rather than a partner. Doug Bock Clark, ProPublica, 13 Apr. 2026 Information-sharing by US AI companies about adversarial distillation echoes a standard practice in the cybersecurity industry, where firms regularly swap data on attacks and adversaries’ tactics as a way to strengthen network defenses. Bloomberg, Mercury News, 7 Apr. 2026 See All Example Sentences for adversarial

Word History

First Known Use

1839, in the meaning defined above

Time Traveler
The first known use of adversarial was in 1839

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Cite this Entry

“Adversarial.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/adversarial. Accessed 22 Apr. 2026.

Kids Definition

adversarial

adjective
ad·​ver·​sar·​i·​al ˌad-vər-ˈser-ē-əl How to pronounce adversarial (audio)
: involving two people or two sides who oppose each other

Legal Definition

adversarial

adjective
ad·​ver·​sar·​i·​al ˌad-vər-ˈser-ē-əl How to pronounce adversarial (audio)
: of, relating to, or characteristic of an adversary or adversary procedures : adversary

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