Source : Webster's Revised Unabridged Dictionary (1913)

Moonstruck \Moon"struck`\, a.
   1. Mentally affected or deranged by the supposed influence of
      the moon; lunatic.

   2. Produced by the supposed influence of the moon.
      ``Moonstruck madness.'' --Milton.

   3. Made sick by the supposed influence of the moon, as a
      human being; made unsuitable for food, as fishes, by such
      supposed influence.

Source : WordNet®

moonstruck
     adj : insane and believed to be affected by the phases of the moon
           [syn: {lunatic}]