Word:
concussion

Context Sentence:
A violent attack in Leamington left a Warwick student with severe concussion and in need of hospital treatment.

Source:
'Group of students attacked in Leamington' in Warwick Boar Issue 12 Volume 29 Tuesday 23 January 2007

Definition:
n.
injury to the brain caused by a blow, violent shaking, etc, resulting in temporary unconsciousness

e,g: The patient is suffering from severe concussion following a blow to the head.