concussion -
An injury to part of the body, most especially the brain, caused by a violent blow, followed by loss of function.
concussion -
The unlawful forcing of another by threats of violence to yield up something of value.
Wikipedia
Concussion, from the Latin concutere ("to shake violently") or the Latin concussus ("action of striking together"), is the most common type of traumatic brain injury. The terms mild brain injury, mild traumatic brain injury (MTBI), mild head injury (MHI), and minor head trauma and concussion may be used interchangeably, although the latter is often treated as a narrower category. The term "concussion" has been used for centuries and is still commonly used in sports medicine, while 'MTBI' is a technical term used more commonly nowadays in general medical contexts.
