Source : Webster's Revised Unabridged Dictionary (1913)

Naumachy \Nau"ma*chy\, n. [L. naumachia, Gr. ?; ? ship + ?
   fight, battle, ? to fight.]
   1. A naval battle; esp., a mock sea fight.

   2. (Rom. Antiq.) A show or spectacle representing a sea
      fight; also, a place for such exhibitions.

Source : WordNet®

naumachy
     n : a naval spectacle; a mock sea battle put on by the ancient
         Romans [syn: {naumachia}]