It has several interpretations as a noun and as a verb, but they are all related to a flat, thin surface. It is understood as "sheet, sheet of paper, face of a nautical sail, cape or cover, shroud, sheet music, . . . " which can also be used as "the part of the ground that covers a rain" or the "hatch that serves to stretch the sails in a ship". It surely has a proto-Germanic origin, which came into Old English as sceat and evolved in the Middle Ages as schete ("length of cloth").
