An opponent or rival.

(religion, Christianity) The Devil; Satan.

plural of adversary

Characteristic of, or in the manner of, an adversary; combative, hostile, opposed.

In an adversarial way.

Quality of being adversary.

(archaic) hostile; adversarial

The quality of being adversarial.

The quality of being adversarial.

(law) A system of law in which advocates represent the prosecution and the defence and an impartial person (judge) or people (jury) determine the truth of the matter