freewheel

a mechanism in the hub of the rear wheel of a bicycle that enables the rear wheel to continue to rotate when the rider stops pedaling

a mechanism in the transmission of a motor vehicle that disengages the drive shaft and allows it to rotate freely when revolving at a higher speed than the engine shaft

to continue moving on a bicycle or in a vehicle without using power to drive the wheels

to live or act without conventional constraints, purpose, or regard for responsibilities

to move on a bicycle without moving the pedals, or to move in a car without switching on the engine, usually down a slope