is a specific kind of: lever.

is a broader term that covers: accelerator, accelerator pedal, gas, gas pedal, gun, throttle | brake pedal | clutch, clutch pedal | soft pedal | loud pedal, sustaining pedal.

is a part of: bicycle, bike, cycle, wheel | automotive vehicle, motor vehicle | organ, pipe organ.

derivation: treadle | bicycle, bike, cycle, pedal, wheel.