concussion

 
Pronunciation: /kənˈkʌʃ(ə)n/

noun

  • 1 [mass noun] temporary unconsciousness or confusion and other symptoms caused by a blow on the head: he was carried off the pitch with concussion [count noun]: nothing more serious than a mild concussion
  • 2a violent shock as from a heavy blow: the ground shuddered with the concussion of the blast

Origin:

late Middle English: from Latin concussio(n-), from the verb concutere 'dash together, shake' (see concuss)