rudder
/ˈrʌdə(r); `rʌdɚ/ n
(a) broad flat piece of wood or metal hinged vertically at the stern of a boat or ship, used for steering （船的）舵. =>illus at yacht 见yacht插图.
(b) similar piece of metal on the rear of an aircraft, for the same purpose （飞机的）方向舵. =>illus at aircraft 见 aircraft 插图.