mopcorn
Popcorn found on the floor of a movie theatre after the movie has ended. Eating mopcorn is a way to save yourself some money by avoiding the $17 buckets that they sell at the concession stand.
Mortimer took his smokin' hot date out to see a midnight screening of Donnie Darko at the dollar theatre and saved money by eating mopcorn so that he had enough to smuggle in four bottles of wild irish rose.