Source : Webster's Revised Unabridged Dictionary (1913)

Scaleboard \Scale"board`\ (?; commonly ?), n. [3d scale +
   board.]
   1. (Print.) A thin slip of wood used to justify a page.
      [Obs.] --Crabb.

   2. A thin veneer of leaf of wood used for covering the
      surface of articles of furniture, and the like.

   {Scaleboard plane}, a plane for cutting from a board a wide
      shaving forming a scaleboard.