freewheel

free +‎ wheel

freewheel (plural freewheels)

1. a device in a transmission that disengages the driveshaft from the driven shaft when the driven shaft rotates faster than the driveshaft.

freewheel (third-person singular simple present freewheels, present participle freewheeling, simple past and past participle freewheeled)

1. (of a gear) To continue spinning after disengagement.
2. (of a cyclist) To ride a bicycle without pedalling, e.g. downhill.
   • 1935, George Orwell, A Clergyman’s Daughter, Chapter 3,

     On her elderly bicycle with the basketwork carrier on the handle-bars, Dorothy free-wheeled down the hill, doing mental arithmetic with three pounds nineteen and fourpence--her entire stock of money until next quarter-day.

3. (of a motorist) To operate a motor vehicle which is coasting without power, e.g. downhill.
4. (by extension) To operate free from constraints.