The Collaborative International Dictionary of English v.0.48:

Piling \Pil"ing\, n. [See Pile a stake.]
   A series of piles; piles considered collectively; as, the
   piling of a bridge.
   [1913 Webster]

   Pug piling, sheet piles connected together at the edges by
      dovetailed tongues and grooves.

   Sheet piling, a series of piles made of planks or half logs
      driven edge to edge, -- used to form the walls of
      cofferdams, etc.
      [1913 Webster]