Source : Webster's Revised Unabridged Dictionary (1913)

Bogy \Bo"gy\, n.; pl. {Bogies}. [See {Bogle}.]
   A specter; a hobgoblin; a bugbear. ``Death's heads and
   bogies.'' --J. H. Newman. [Written also {bogey}.]

         There are plenty of such foolish attempts at playing
         bogy in the history of savages.          --C. Kingsley.

Source : WordNet®

bogy
     n 1: an unidentified (and possibly enemy) aircraft [syn: {bogie},
           {bogey}]
     2: an evil spirit [syn: {bogey}, {bogie}]