PILE (3)

Pile, n. [[AS. pīl arrow, stake, L. pilum javelin; but cf. also L. pila pillar.]] 1. 1. A large stake, or piece of timber, pointed and driven into the earth, as at the bottom of a river, or in a harbor where the ground is soft, for the support of a building, a pier, or other superstructure, or to form a cofferdam, etc.
☞ Tubular iron piles are now much used. 2. 2. [[Cf. F. pile.]] (Her.) One of the ordinaries or subordinaries having the form of a wedge, usually placed palewise, with the broadest end uppermost.
Pile bridge, a bridge of which the roadway is supported on piles. — Pile cap, a beam resting upon and connecting the heads of piles. — Pile driver, or Pile engine, an apparatus for driving down piles, consisting usually of a high frame, with suitable appliances for raising to a height (by animal or steam power, the explosion of gunpowder, etc.) a heavy mass of iron, which falls upon the pile. — Pile dwelling. See Lake dwelling, under Lake. — Pile plank (Hydraul. Eng.), a thick plank used as a pile in sheet piling. See Sheet piling, under Piling. — Pneumatic pile. See under Pneumatic. — Screw pile, one with a screw at the lower end, and sunk by rotation aided by pressure.