rudder

 
Pronunciation: /ˈrʌdə/

noun

  • a flat piece hinged vertically near the stern of a boat or ship for steering.
  • a vertical aerofoil pivoted from the tailplane of an aircraft, for controlling movement about the vertical axis.
  • [mass noun] application of a rudder in steering a boat, ship, or aircraft: bring the aircraft to a stall and apply full rudder a small amount of extra rudder

Origin:

Old English rōther 'paddle, oar', of West Germanic origin; related to Dutch roer, German Ruder, also to the verb row2