furring strips

noun

1. fur used for trimming or lining
2. the act of trimming, lining, etc. with fur
3. a coating of diseased or waste matter, as on the tongue
4. 1. the fastening of thin strips of wood or metal as to joists, studs, or masonry walls in order to form a level backing for flooring, plaster, etc. or to provide air spaces
   2. the strips so used
      in full furring strips