Source : Webster's Revised Unabridged Dictionary (1913)

Parallelopipedon \Par`al*lel`o*pip"e*don\, n. [NL.]
   A parallelopiped. --Hutton.

Source : WordNet®

parallelopipedon
     n : a prism whose bases are parallelograms [syn: {parallelepiped},
          {parallelopiped}, {parallelepipedon}]