0 a part attached to a chair, especially a seat in a car, that supports the head and stops it from moving too far back:
Gordon credited his head restraint with saving his life in a crash.
A lack of head restraint was the culprit in many racing injuries.
The rear seats can easily be folded, without having to remove the head restraints.
Millions of motorists and their passengers are risking neck injuries because of badly positioned head restraints.
