Source : Webster's Revised Unabridged Dictionary (1913)

Solid \Sol"id\, n.
   1. A substance that is held in a fixed form by cohesion among
      its particles; a substance not fluid.

   2. (Geom.) A magnitude which has length, breadth, and
      thickness; a part of space bounded on all sides.

   {Solid of revolution}. (Geom.) See {Revolution}, n., 5.