Source : Webster's Revised Unabridged Dictionary (1913)

Prosecutor \Pros"e*cu`tor\, n. [Cf. L. prosecutor an attendant.]
   1. One who prosecutes or carries on any purpose, plan, or
      business.

   2. (Law) The person who institutes and carries on a criminal
      suit against another in the name of the government.
      --Blackstone.

Source : WordNet®

prosecutor
     n : a government official who conducts criminal prosecutions on
         behalf of the state [syn: {public prosecutor}, {prosecuting
         officer}, {prosecuting attorney}]