adversary

[ad-ver-ser-ee] /ˈæd vərˌsɛr i/
noun, plural adversaries.
1.
a person, group, or force that opposes or attacks; opponent; enemy; foe.
2.
a person, group, etc., that is an opponent in a contest; contestant.
3.
the Adversary, the devil; Satan.
adjective, Also, especially British, adversarial
[ad-ver-sair-ee-uh l] /ˌæd vərˈsɛər i əl/ (Show IPA)
4.
of or pertaining to an adversary.
5.
involving adversaries, as plaintiff and defendant in a legal proceeding:
an adversary trial.
Origin
1300-50; Middle English adversarie < Latin adversārius, equivalent to advers(us) (see adverse) + -ārius -ary; replacing Middle English adversere < Anglo-French
Related forms
adversariness, noun
nonadversarial, adjective
Synonyms
1. Adversary, antagonist mean a person or a group contending against another. Adversary suggests an enemy who fights determinedly, continuously, and relentlessly: a formidable adversary. Antagonist suggests one who, in hostile spirit, opposes another, often in a particular contest or struggle: a duel with an antagonist.
Antonyms
1. ally.
Examples from the web for adversarial
  • It's an adversarial system, to be sure, but that hardly means that the adversaries can't recognize their opposite number.
  • But those faculty ties have not created an adversarial relationship with presidents.
  • If the whole of how science is done is, as you say, an adversarial conflict that only rewards who.
  • Communication between players is more collaborative than adversarial.
  • Ever remembered as a protagonist of fair play in the adversarial arena.
  • It was the trendiness and sectarianism of literary studies that made him seem ever tactical and adversarial.
  • Their relationship with exchanges need not be wholly adversarial.
  • They could have approached the genetic testing services in a less adversarial manner.
  • But it creates an adversarial relationship: the president on one side of the podium, the press on the other.
  • The two countries are not enemies, but their relationship is explicitly adversarial.
British Dictionary definitions for adversarial

adversarial

/ˌædvɜːˈsɛərɪəl/
adjective
1.
pertaining to or characterized by antagonism and conflict
2.
(Brit) having or involving opposing parties or interests in a legal contest US term adversary

adversary

/ˈædvəsərɪ/
noun (pl) -saries
1.
a person or group that is hostile to someone; enemy
2.
an opposing contestant in a game or sport
adjective
3.
the US term for adversarial (sense 2)
Word Origin
C14: from Latin adversārius, from adversus against. See adverse
Word Origin and History for adversarial
adj.

by 1892, from adversary + -al (1). Probably coined to avoid confusion which might arise with use of adversary (adj.), which is attested from late 14c. Related: Adversarially.

adversary

n.

mid-14c., aduersere, from Anglo-French adverser (13c.), Old French adversaire "adversary, opponent, enemy," or directly from Latin adversarius "opponent, adversary, rival," noun use of adjective meaning "opposite, hostile, contrary," literally "turned toward one," from adversus "turned against" (see adverse). The Latin word is glossed in Old English by wiðerbroca.

adversarial in the Bible

(Heb. satan), an opponent or foe (1 Kings 5:4; 11:14, 23, 25; Luke 13:17); one that speaks against another, a complainant (Matt. 5:25; Luke 12:58); an enemy (Luke 18:3), and specially the devil (1 Pet. 5:8).