Source : Webster's Revised Unabridged Dictionary (1913)

Surbase \Sur"base`\, n. [Pref. sur- + base.]
   1. (Arch.) A cornice, or series of moldings, on the top of
      the base of a pedestal, podium, etc. See Illust. of
      {Column}.

   2. A board or group of moldings running round a room on a
      level with the tops of the chair backs. --Knight.

Source : WordNet®

surbase
     n : the molding or border above the base of a structure (a
         pedestal or podium or wall)