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

But both Venezuela's geography and its weak security institutions may also frustrate attempts to quickly and efficiently establish robust governance capable of countering the presence of dug-in adversarial forces. —Tom O'Connor, MSNBC Newsweek, 25 Nov. 2025

The politicians' public rhetoric prior to the meeting was adversarial, so many were surprised when the mayor-elect’s visit went so smoothly. —Bailey Richards, PEOPLE, 23 Nov. 2025

Polanco said Mamdani needs to keep that firmly in mind, especially since the two have previously taken an adversarial tone. —Jesse Zanger, CBS News, 21 Nov. 2025

Crucially, this ability to jailbreak with adversarial poems isn’t just a gap in one particular software’s armor. —James Folta, Literary Hub, 21 Nov. 2025

Word History

Etymology

adversary entry 1 + -al entry 1

First Known Use

1839, in the meaning defined above

Rhymes for adversarial

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

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