An American sandwich with a dish of ground beef, onions, sweetened tomato sauce or ketchup and other seasonings, and served on a hamburger bun. The name "sloppy" comes from the fact that eating it as if it were a normal sandwich often results in the meat and sauce spilling out, therefore making it sloppy to eat. It may also be served "open face", with the bun halves or slices of bread next to each other and the meat on top of each.