I. R ˈadvə(r)ˌserē, -R -vəˌs-; -ri noun
( -es )
Etymology: Middle English, from Middle French & Latin; Middle English adversere, from Middle French adversier, from Latin adversarius; Middle English adversarie, from Latin adversarius, from adversarius, adjective, turned toward, antagonistic toward, from adversus (past participle of advertere to turn to) + -arius -ary — more at advert
1. : one that contends with, opposes, or resists : antagonist , opponent , enemy , foe
do as adversaries do in law, strive mightily but eat and drink as friends — Shakespeare
powers of sarcasm that made him feared as an adversary
the sea powers have repeatedly succeeded in defeating their continental adversaries — G.H.Miller
2.
a. : an opponent in a game
b. : an opponent of the declarer in the game of bridge or of the player who plays the dummy
II. adjective
Etymology: Middle English, from Latin adversarius
1. archaic : opposed , adverse , antagonistic
2. : having or involving opposing antagonistic parties or interests : involving the Anglo-American system of procedure for conducting trials under strict rules of evidence with the right of cross-examination and argument, one party with his witnesses striving to prove the facts essential to his case and the other party striving to disprove those facts or to establish an affirmative defense : contested , litigated