#pinion  a gear with a small number of teeth designed to mesh with a larger wheel or rack
  supertype:  #gear_wheel__gear__cogwheel  a toothed wheel that engages another toothed mechanism in order to change the speed or direction of transmitted motion
  subtype:  #lantern_pinion__lanternpinion__lantern_wheel__lanternwheel  a small pinion having cylindrical bars instead of teeth, used chiefly in inexpensive clocks

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