Any small to fairly sized object that falls between the cushions of a couch, commonly rediscovered after as much as a year of confinement in said furniture. Notable types include Goldfish, Cheez-Its, and popcorn, though more essential living room items, such as TV remotes, have been found, as well.
I found a Hershey's Kiss futon crouton the other day in my Ikea couch. Gave it a sniff to make sure there was no stank and I popped that motherfucker in my mouth.