Tether

A tether is a cord, fixture, or flexible attachment that characteristically anchors something movable to something fixed; it also may be used to connect two movable objects, such as an item being towed by its tow. Applications for tethers include: fall arrest systems, lanyards, balloons, kites, airborne wind-power systems, anchors, floating water power systems, towing, animal constraint, space walks, power kiteing, and anti-theft devices.