Main Entry:

rud·der

Pronunciation:

\ˈrə-dər\

Function:

noun

Etymology:

Middle English rother, from Old English rōther paddle; akin to Old English rōwan to row

Date:

14th century

1 : an underwater blade that is positioned at the stern of a boat or ship and controlled by its helm and that when turned causes the vessel's head to turn in the same direction 2 : a movable auxiliary airfoil on an airplane usually attached at the rear end that serves to control direction of flight in the horizontal plane — see airplane illustration 3 : a guiding force or strategy

— rud·der·less \-ləs\ adjective