[noun] [U] - temporary damage to the brain caused by a fall or hit on the head or by violent shaking, and resulting in various effects, such as a loss of consciousness and a desire to vomitHe's been a bit dizzy and confused since the accident. Do you think it's mild concussion?
CONCUSSION
Meaning of CONCUSSION in English
Cambridge English vocab. Кембриджский английский словарь. 2012