The term "head restraint" refers to a device that is placed on a chair or car seat to support the head and neck and prevent whiplash injuries during sudden stops or accidents. There are several synonyms for this term, including "headrest," "neck support," "cervical support," and "head cushion." Other terms used to describe this device include "seatback restraint," "car seat headrest," and "automobile neck support." While the terms may differ, their purpose and function remain the same: to provide crucial support to the head and neck during times of sudden movement or impact.