A type of snack that is considered a last resort. When all the good snacks are gone, you are forced to fill your appetite with only slum snacks.
Slum: Verb, \"sləm"\ to go somewhere or do something that might be considered beneath one's station —sometimes used with it
Snack: Noun, \ ˈsnak \; a light meal : food eaten between regular meals
Johnny looked into the cupboard when he was hungry and to his dismay, found nothing but slum snacks.