Source : Webster's Revised Unabridged Dictionary (1913)

Courier \Cou"ri*er\ (k??"r?-?r), n. [F. courrier, fr. courre,
   courir, to run, L. currere. See {Course}, {Current}.]
   1. A messenger sent with haste to convey letters or
      dispatches, usually on public business.

            The wary Bassa . . . by speedy couriers, advertised
            Solyman of the enemy's purpose.       --Knolles.

   2. An attendant on travelers, whose business it is to make
      arrangements for their convenience at hotels and on the
      way.

Source : WordNet®

courier
     n : a person who carries a message [syn: {messenger}]