\Fur"ring\, n.
1. (Carp.)
   (a) The leveling of a surface, or the preparing of an air
       space, by means of strips of board or of larger
       pieces. See {Fur}, v. t., 3.
   (b) The strips thus laid on.

2. (Shipbuilding) Double planking of a ship's side.

3. A deposit from water, as on the inside of a boiler; also,
   the operation of cleaning away this deposit.