Cut-off

Webster's Dictionary of the English Language

·noun That which cuts off or shortens, as a nearer passage or road.

II. Cut-off ·noun Any device for stopping or changing a current, as of grain or water in a spout.

III. Cut-off ·noun 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.