Source : Webster's Revised Unabridged Dictionary (1913)

Ghoul \Ghoul\, n. [Per. gh?l an imaginary sylvan demon, supposed
   to devour men and animals: cf. Ar. gh?l, F. goule.]
   An imaginary evil being among Eastern nations, which was
   supposed to feed upon human bodies. [Written also {ghole} .]
   --Moore.

Source : WordNet®

ghoul
     n 1: someone who takes bodies from graves and sells them for
          anatomical dissection [syn: {graverobber}, {body
          snatcher}]
     2: an evil spirit or ghost