Source : Webster's Revised Unabridged Dictionary (1913)

Polyhedral \Pol`y*he"dral\, Polyhedrical \Pol`y*hed"ric*al\, a.
   [See {Polyhedron}.] (Geom.)
   Having many sides, as a solid body.

   {Polyhedral angle}, an angle bounded by three or more plane
      angles having a common vertex.

Source : WordNet®

polyhedral angle
     n : the space enclosed by three or more planes that intersect in
         a vertex