The hangover like symptoms that are induced by copious amounts of sleep.
Symptoms include extreme grogginess, aches, and general crankiness after sleeping an extreme amount that you aren't used to. No illegal substances involved. Usually after 12+ hours of sleep.
Friend 1: "Jesus, we just slept 14 hours after that forensics trip."
Friend 2: "I know. I feel like I have been hit by a train."
Friend 1: "Damn sleepovers."