The sore throat, grogginess, stiffness, and other symptoms that follow a long night of karaoke. Similar to a hangover but the result of putting on a heckuva show, not alcohol. Spoken either as "kah-rah-over" or "carry-over."
A: Dude, you look like hell. I didn't think you were that drunk last night.
B: I wasn't. It's a karaover.
A: Yeah, you rocked that shit.