Freewheel

Full definition of freewheel

Noun

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

Verb

1. (of a gear) To continue spinning after disengagement.
2. (of a cyclist) To ride a bicycle without pedalling, e.g. downhill.
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.