\Op*po"nent\, a. [L. opponens, -entis, p. pr. of
opponere to set or place against, to oppose; ob (see {Ob-}) +
ponere to place. See {Position}.]
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}.