rudder
/ˈrʌdə(r)/noun
1- a flat piece hinged vertically near the stern of a boat or ship for steering（船的）舵。
1.1
- a vertical aerofoil pivoted from the tailplane of an aircraft, for controlling movement about the vertical axis（飞机的）方向舵, 舵。
1.2
- mass noun application of a rudder in steering a boat, ship, or aircraft（操纵船或飞机航向时的）掌舵：
bring the aircraft to a stall and apply full rudder
使飞机发动机停转并掌满舵
a small amount of extra rudder.
稍稍补加舵的转向程度。
词源
Old English rōther 'paddle, oar', of West Germanic origin; related to Dutch roer, German Ruder, also to the verb ROW2.