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

Several parties in the fragmented Spanish legislature would not back Feijóo, especially the separatist factions which have had a deeply adversarial relationship with the PP. — Tim Lister, CNN Money, 21 June 2026

This reveals a fundamental paradigm shift; advanced large language models are now capable of deep adversarial reasoning, discovering complex architectural failures that human teams missed for years. — Sean Stein Smith, Forbes.com, 18 June 2026

Of course, Pussy Riot’s adversarial relationship with the Russian leader goes way back. — Lina Lecaro, SPIN, 17 June 2026

The relationship started off more adversarial. — James L. Edwards Iii, New York Times, 3 June 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