The Collaborative International Dictionary of English v.0.48:

Walling \Wall"ing\, n.
   1. The act of making a wall or walls.
      [1913 Webster]

   2. Walls, in general; material for walls.
      [1913 Webster]

   Walling wax, a composition of wax and tallow used by
      etchers and engravers to make a bank, or wall, round the
      edge of a plate, so as to form a trough for holding the
      acid used in etching, and the like. --Fairholt.
      [1913 Webster]