adversarial

adjective

ad·​ver·​sar·​i·​al ˌad-vər-ˈser-ē-əl 

ˌad-və-, 

-ˈse-rē-

: 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

Synonyms of adversarial

• hostile
• negative

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

This threat isn’t about adversarial prompts but what happens when autonomous actors inherit enterprise-scale trust. — Itamar Apelblat, Forbes.com, 21 July 2026

Short for adversarial hallucination squatting, HalluSquatting is built on an LLM’s inherent tendency to hallucinate the resource identifiers hosted in repositories and registries. — Dan Goodin, ArsTechnica, 8 July 2026

By doing so, Congress is effectively inviting hackers and fraudsters into our digital wallets and opening the door for adversarial foreign networks to access the private financial data of American citizens. — Raquel Mitchell, Boston Herald, 8 July 2026

This method connects physical commercial hardware, such as inverters and batteries, to a digital grid simulator to safely evaluate how the software handles rapid voltage shifts and adversarial disruptions. — Mrigakshi Dixit, Interesting Engineering, 6 July 2026

Word History

Etymology

adversary entry 1 + -al entry 1

First Known Use

1839, in the meaning defined above

Rhymes for adversarial

• biserial
• filarial
• malarial
• subaerial
• actuarial
• secretarial
• urticarial
• aerial
• areal
• ariel
• burial
• antimalarial

Kids Definition

adversarial

adjective

ad·​ver·​sar·​i·​al ˌad-vər-ˈser-ē-əl 

: involving two people or two sides who oppose each other

Legal Definition

adversarial

adjective

ad·​ver·​sar·​i·​al ˌad-vər-ˈser-ē-əl 

: of, relating to, or characteristic of an adversary or adversary procedures : adversary