The meatballs provided by most school cafeterias or any other eatery that is usually cheap, dirty, and/or served by filthy individuals. Slamballs typically are made up of one key ingredient, grade Z ground beef and are somehow satisfyingly tasty even though the consequences of the slamball are usually not worth it. Should usually be passed on but often is not.
Sally: "Let's go make out after 6th period lunch!?!?"
Me: "Normally I would babe, but they are serving slamball hoagies today. I know once I'm done eating I'll need to drop a hammer in the bathroom. Can I get a raincheck on that?"