Source : Webster's Revised Unabridged Dictionary (1913)

Deputy \Dep"u*ty\, n.; pl. {Deputies}. [F. d['e]put['e], fr. LL.
   deputatus. See {Depute}.]
   1. One appointed as the substitute of another, and empowered
      to act for him, in his name or his behalf; a substitute in
      office; a lieutenant; a representative; a delegate; a
      vicegerent; as, the deputy of a prince, of a sheriff, of a
      township, etc.

            There was then [in the days of Jehoshaphat] no king
            in Edom; a deputy was king.           --1 Kings
                                                  xxii. 47.

            God's substitute, His deputy anointed in His sight.
                                                  --Shak.

   Note: Deputy is used in combination with the names of various
         executive officers, to denote an assistant empowered to
         act in their name; as, deputy collector, deputy
         marshal, deputy sheriff.

   2. A member of the Chamber of Deputies. [France]

   {Chamber of Deputies}, one of the two branches of the French
      legislative assembly; -- formerly called {Corps
      L['e]gislatif}. Its members, called deputies, are elected
      by the people voting in districts.

   Syn: Substitute; representative; legate; delegate; envoy;
        agent; factor.

Source : WordNet®

deputy
     n 1: someone authorized to exercise the powers of sheriff in
          emergencies [syn: {deputy sheriff}]
     2: an assistant with power to act when his superior is absent
        [syn: {lieutenant}]
     3: a member of the lower chamber of a legislative assembly
        (such as in France)
     4: a person appointed to represent or act on behalf of others
        [syn: {surrogate}]