Source : Webster's Revised Unabridged Dictionary (1913)

Scalenohedron \Sca*le`no*he"dron\ (-dr[o^]n), n. [Gr. skalhno`s
   uneven + "e`dra seat, base.] (Crystallog.)
   A pyramidal form under the rhombohedral system, inclosed by
   twelve faces, each a scalene triangle.