Having suffered a concussion, which is a type of brain injury from a hard impact to the head.
From Latin 'concussus' (shaken), from 'concutere' (to shake violently), made of 'com-' (together) + 'cutere' (to shake). The medical meaning became formalized in the 1800s.
A concussion is literally your brain getting shaken and bruised inside your skull—and the scary part is you can look fine but have serious invisible injuries, which is why doctors take them so seriously now!
Complete word intelligence in one call. Free tier — 50 lookups/day.