opponent
opponent (ə-pōʹnənt) noun
One that opposes another or others in a battle, contest, controversy, or debate.
adjective
1. Acting against an antagonist or opposing force: opponent armies.
2. Located in front.
[Latin oppōnēns, oppōnent- present participle of oppōnere, oppose. See oppose.]
oppoʹnency noun
Synonyms: opponent, adversary, antagonist. These nouns all mean one who offers opposition. An opponent opposes, resists, or combats: "two men, one . . . a zealous supporter and the other a zealous opponent of the system pursued" (Macaulay). Adversary suggests a more formidable opponent and can imply animosity: "the Adversary of God and Man,/Satan" (John Milton). "And do as adversaries do in law,/Strive mightily, but eat and drink as friends" (Shakespeare). An antagonist is an actively hostile opponent: "He that wrestles with us strengthens our nerves, and sharpens our skill. Our antagonist is our helper" (Edmund Burke). See also synonyms at enemy.