The word 'concussion' has several meanings and applications that are controversial. This paper attempts to trace the historical origins and evolution of the descriptive classifications of concussive head injuries. It is suggested that head injuries should be described on the available evidence of the severity and duration of altered consciousness, traumatic amnesia and, when present, the variably associated neurological, physiological and imaging signs. The word concussion reflects an overenthusiastic trend in medical labelling. Since our understanding of types of brain injury and their symptoms and sequelae has advanced, the term should be abandoned.