His ancient knot of dangerous adversaries.  --Shak.
   Agree with thine adversary quickly.         --Matt. v. 25.
   It may be thought that to vindicate the permanency of
   truth is to dispute without an adversary.   --Beattie.
{The Adversary}, The Satan, or the Devil.
Syn: {Adversary}, {Enemy}, {Opponent}, {Antagonist}.
Usage: Enemy is the only one of these words which necessarily
       implies a state of personal hostility. Men may be
       adversaries, antagonists, or opponents to each other
       in certain respects, and yet have no feelings of
       general animosity. An adversary may be simply one who
       is placed for a time in a hostile position, as in a
       lawsuit, an argument, in chess playing, or at fence.
       An opponent is one who is ranged against another
       (perhaps passively) on the opposing side; as a
       political opponent, an opponent in debate. An
       antagonist is one who struggles against another with
       active effort, either in a literal fight or in verbal
       debate.