Furring \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.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Fur \Fur\, v. t. [imp. & p. p. Furred; p. pr. & vb. n. Furring.]

1. To line, face, or cover with fur; as, furred robes. ``You fur your gloves with reason.'' --Shak.

2. To cover with morbid matter, as the tongue.

3. (Arch.) To nail small strips of board or larger scantling upon, in order to make a level surface for lathing or boarding, or to provide for a space or interval back of the plastered or boarded surface, as inside an outer wall, by way of protection against damp. --Gwill.

Source: Webster's Revised Unabridged Dictionary (1913)