The Collaborative International Dictionary of English v.0.48:

Messenger \Mes"sen*ger\, n. [OE. messager, OF. messagier, F.
   messager. See Message.]
   1. One who bears a message; the bearer of a verbal or written
      communication, notice, or invitation, from one person to
      another, or to a public body; specifically, an office
      servant who bears messages.
      [1913 Webster]

   2. One who, or that which, foreshows, or foretells.
      [1913 Webster]

            Yon gray lines
            That fret the clouds are messengers of day. --Shak.
      [1913 Webster]

   3. (Naut.) A hawser passed round the capstan, and having its
      two ends lashed together to form an endless rope or chain;
      -- formerly used for heaving in the cable.
      [1913 Webster]

   4. (Law) A person appointed to perform certain ministerial
      duties under bankrupt and insolvent laws, such as to take
      charge of the estate of the bankrupt or insolvent.
      --Bouvier. Tomlins.
      [1913 Webster]

   Syn: Carrier; intelligencer; courier; harbinger; forerunner;
        precursor; herald.
        [1913 Webster]

   Messenger bird, the secretary bird, from its swiftness.
      [1913 Webster]

WordNet (r) 3.0 (2006):

messenger
    n 1: a person who carries a message [syn: messenger,
         courier]

Moby Thesaurus II by Grady Ward, 1.0:

58 Moby Thesaurus words for "messenger":
   Hermes, Mercury, Pheidippides, ancestor, announcer, antecedent,
   avant-garde, bellwether, buccinator, buccinator novi temporis,
   bushwhacker, commissar, commissary, commissionaire, commissioner,
   courier, delegate, emissary, envoy, explorer, forebear, foregoer,
   forerunner, foreshadower, front runner, frontiersman, fugleman,
   go-between, gofer, groundbreaker, guide, harbinger, herald,
   innovator, intermediary, lead runner, leader, legate, minister,
   nuncio, page, pathfinder, pioneer, point, precedent, precursor,
   predecessor, premonitor, presager, runner, scout, secretary,
   stormy petrel, trailblazer, trailbreaker, vanguard, vaunt-courier,
   voortrekker



Easton's 1897 Bible Dictionary:

Messenger
   (Heb. mal'ak, Gr. angelos), an angel, a messenger who runs on
   foot, the bearer of despatches (Job 1:14; 1 Sam. 11:7; 2 Chr.
   36:22); swift of foot (2 Kings 9:18).


Bouvier's Law Dictionary, Revised 6th Ed (1856):

MESSENGER. A person appointed to perform certain duties, generally of a
ministerial character.
     2. In England, a messenger appointed under the bankrupt laws, is an
officer who is authorized to execute the lawful commands of commissioners of
bankrupts.