1. Of a boxer, to be disoriented from a particularly heavy punch or too many blows to the head. That boxer was punch-drunk after being knocked out in the ring—he couldn't even remember his name!
2. To be disoriented from exhaustion. I'm punch-drunk after taking exams all week long. Of course he's punch-drunk—he's been driving for 12 hours straight!
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.