OPPONENT
opponent, opposing
(adjective) characterized by active hostility; “opponent (or opposing) armies”
adversary, antagonist, opponent, opposer, resister
(noun) someone who offers opposition
opposition, opponent, opposite
(noun) a contestant that you are matched against
Source: WordNet® 3.1
Etymology
Noun
opponent (plural opponents)
One who opposes another; one who works or takes a position against someone or something; one who attempts to stop the progress of someone or something.
One who opposes another physically (in a fight, sport, game, or competition).
One who opposes another in words (in a dispute, argument or controversy).
One who is opposed or objects (to a policy, course of action or set of ideas).
(historical) The participant who opens an academic debate by putting forward objections to a theological or philosophical thesis.
Synonyms
• adversary
• antagonist
Antonyms
• (one who opposes): supporter, proponent, advocate
• (person who opens an academic debate): respondent
Adjective
opponent (comparative more opponent, superlative most opponent)
(obsolete) Opposing; adverse; antagonistic.
(obsolete) Situated in front; opposite.
Source: Wiktionary
Op*po"nent, a. Etym: [L. opponens, -entis, p.pr. of opponere to set
or place against, to oppose; ob (see Ob-) + ponere to place. See
Position.]
Definition: Situated in front; opposite; hence, opposing; adverse;
antagonistic. Pope.
Op*po"nent, n.
1. One who opposes; an adversary; an antagonist; a foe. Macaulay.
2. One who opposes in a disputation, argument, or other verbal
controversy; specifically, one who attacks some theirs or
proposition, in distinction from the respondent, or defendant, who
maintains it.
How becomingly does Philopolis exercise his office, and seasonably
commit the opponent with the respondent, like a long-practiced
moderator! Dr. H. More.
Syn.
– Antagonist; opposer; foe. See Adversary.
Source: Webster’s Unabridged Dictionary 1913 Edition