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.
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   2. One who, or that which, foreshows, or foretells.
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            Yon gray lines
            That fret the clouds are messengers of day. --Shak.
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   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.
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   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.
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   Syn: Carrier; intelligencer; courier; harbinger; forerunner;
        precursor; herald.
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   Messenger bird, the secretary bird, from its swiftness.
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WordNet (r) 3.0 (2006):

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