The condition experienced the day following extreme over-consumption of beer, when symptoms of a concussion are exhibited; e.g., head pain, dizziness, loss of coordination, double vision, vomiting, nausea, memory loss.
Akin to a normal hangover, but specifically due to beer consumption.
"Bro... I downed so many Milwaukee's Beasts last night at the kegger, that I think I have a beercussion!"
A fine example of this is likely available within your own family tree. Man you'd need a car jack to fuck your Aunt Katie with that crazy ass Beer Pussy.