(1):
(n.) The valve gearing or mechanism by which steam is cut off from entering the cylinder of a steam engine after a definite point in a stroke, so as to allow the remainder of the stroke to be made by the expansive force of the steam already let in. See Expansion gear, under Expansion.
(2):
(n.) Any device for stopping or changing a current, as of grain or water in a spout.
(3):
(n.) That which cuts off or shortens, as a nearer passage or road.