An act of combustion that takes place either atop, or inside a couch. The couch burns, along with anyone unfortunate enough to be on the couch at the time, as everyone knows couches are fortresses that trap anyone from attempting to escape their impending doom.
Step 1 - take couch to wilderness, bring plenty of beer Step 2 - start bonfire - get smashed - sit on couch with friends and reminisce.
Step 3 - when well smashed and bonfire needs more fuel, add couch to fire.
Billy - Hey Sally, should we reupholster this thing?