·noun A vertical cleated drum or cylinder, revolving on an upright spindle, and surmounted by a drumhead with sockets for bars or levers. It is much used, especially on shipboard, for moving or raising heavy weights or exerting great power by traction upon a rope or cable, passing around the drum. It is operated either by steam power or by a number of men walking around the capstan, each pushing on the end of a lever fixed in its socket.