Source : Webster's Revised Unabridged Dictionary (1913)

Manes \Ma"nes\, n. pl. [L.] (Rom. Antiq.)
   The benevolent spirits of the dead, especially of dead
   ancestors, regarded as family deities and protectors.

         Hail, O ye holy manes!                   --Dryden.

Source : WordNet®

Manes
     n : a Persian prophet who founded Manichaeism (216-276)