Source : Webster's Revised Unabridged Dictionary (1913)

Eyewitness \Eye"wit`ness\, n.
   One who sees a thing done; one who has ocular view of
   anything.

         We . . . were eyewitnesses of his majesty. --2 Pet. i.
                                                  16.

Source : WordNet®

eyewitness
     n : a spectator who can describe what happened