adversary n: one that contends with or opposes another
: any of the opposing parties in a legal action
adj : of, relating to, or involving opposing parties or interests
: of, relating to, or involving a system of justice in which opposing parties usually represented by counsel present evidence to an impartial decision-maker (as a jury) by a process of questioning witnesses under the supervision of a judge compare accusatorial , inquisitorial
Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.