Source : Webster's Revised Unabridged Dictionary (1913)

Ambassador \Am*bas"sa*dor\, Embassador \Em*bas"sa*dor\, n. [See
   {Embassador}.]
   1. A minister of the highest rank sent to a foreign court to
      represent there his sovereign or country.

   Note: Ambassadors are either ordinary [or resident] or
         extraordinary, that is, sent upon some special or
         unusual occasion or errand. --Abbott.

   2. An official messenger and representative.

Embassador \Em*bas"sa*dor\, n. [F. ambassadeur, Sp. embajador,
   LL. ambassiator, ambasciator. See {Embassy}, and cf.
   {Ambassador}.]
   Same as {Ambassador}.

         Stilbon, that was a wise embassadour, Was sent to
         Corinth.                                 --Chaucer.

         Myself my king's embassador will go.     --Dryden.

Source : WordNet®

embassador
     n : a diplomat of the highest rank; accredited as representative
         from one country to another [syn: {ambassador}]