1911 Encyclopædia Britannica/Sail

SAIL, the English equivalent of the common Teutonic word for one of the two universal means of propulsion of a vessel through the water, the other being the oar (q.v.). For the various types of sail see Rigging, and for the textile material used see Sailcloth below. The origin of the O. Eng. segl or segel and its cognates, e.g. Dutch zeil, Dan. seil, Ger. Segel, &c., is not known; it is certainly not connected with the Lat. sagulum, cloak, mantle. It may be derived from the Indo-European root sagh-, seen in Sanskrit sah, endure, the idea being of that which bears up against or resists the wind.