1911 Encyclopædia Britannica/Sleeper

SLEEPER, a term used with many technical applications for a piece of timber, metal, &c, used as a support; in carpentry it is such a piece of timber laid on low cross walls as a plate to receive ground joists; in shipbuilding, a strengthening timber for the bows and stern frame; the most frequent use of the term is for a timber or steel support on which the chairs are fixed for carrying the rails on a railway; in America these are called “ties” (see Railways). The common explanation of the origin of the word is to connect it with “sleep,” the timbers supposed to be lying at rest. The real source of the word is the Norwegian sleip, a piece of timber used for dragging things over, a roller, especially used of timbers laid in a row in making a road. This word Skeat (Etymol. Dict., 1898) connects with “slab,” a flat piece of stone or wood. The French term dormant is used in carpentry, but as part of the frame of a window or door.