Source : Webster's Revised Unabridged Dictionary (1913)

Harbinger \Har"bin*ger\, n. [OE. herbergeour, OF. herbergeor one
   who provides lodging, fr. herbergier to provide lodging, F.
   h['e]berger, OF. herberge lodging, inn, F. auberge; of German
   origin. See {Harbor}.]
   1. One who provides lodgings; especially, the officer of the
      English royal household who formerly preceded the court
      when traveling, to provide and prepare lodgings. --Fuller.

   2. A forerunner; a precursor; a messenger.

            I knew by these harbingers who were coming.
                                                  --Landor.

Harbinger \Har"bin*ger\, v. t. [imp. & p. p. {Harbingered}; p.
   pr. & vb. n. {Harbingering}.]
   To usher in; to be a harbinger of. ``Thus did the star of
   religious freedom harbinger the day.'' --Bancroft.

Source : WordNet®

harbinger
     n : an indication of the approach of something or someone [syn:
         {forerunner}, {herald}, {precursor}]
     v : foreshadow or presage [syn: {announce}, {annunciate}, {foretell},
          {herald}]