Source : Webster's Revised Unabridged Dictionary (1913)

Weatherboarding \Weath"er*board`ing\, n. (Arch.)
   (a) The covering or siding of a building, formed of boards
       lapping over one another, to exclude rain, snow, etc.
   (b) Boards adapted or intended for such use.

Source : WordNet®

weatherboarding
     n : a long thin board with one edge thicker than the other; used
         as siding by lapping one board over the board below [syn:
          {clapboard}, {weatherboard}]