Source : Webster's Revised Unabridged Dictionary (1913)

Accomplice \Ac*com"plice\, n. [Ac- (perh. for the article a or
   for L. ad) + E. complice. See {Complice}.]
   1. A cooperator. [R.]

            Success unto our valiant general, And happiness to
            his accomplices!                      --Shak.

   2. (Law) An associate in the commission of a crime; a
      participator in an offense, whether a principal or an
      accessory. ``And thou, the cursed accomplice of his
      treason.'' --Johnson.

   Note: It is followed by with or of before a person and by in
         (or sometimes of) before the crime; as, A was an
         accomplice with B in the murder of C. Dryden uses it
         with to before a thing. ``Suspected for accomplice to
         the fire.'' --Dryden.

   Syn: Abettor; accessory; assistant; associate; confederate;
        coadjutor; ally; promoter. See {Abettor}.

Source : WordNet®

accomplice
     n : a person who joins with another in carrying out some plan
         (especially an unethical or illegal plan) [syn: {confederate}]