1. a patty made of ground beef, usually served on a bun with a variety of condiments, such as ketchup, mustard, relish, onions, tomatoes, etc. The hamburger was said to be invented in Seymour, Wisconsin, in 1885, where Outgamie County Fair concessionaire Charles Nagreen, 15, realizing his meatballs weren't selling because people wanted to walk around and enjoy the fair, flattened the meatball, placed it between bread slices and called it a "hamburger." By another account, the sandwich was invented in 1892 in Akron, Ohio, by Akron County Fair concessionaire Frank Menches who, when running out of sausage, ground up the meat he had left and served it as a meat patty. The hamburger got its first widespread attention in 1904 at the St. Louis World's Fair. The most plausible account is that the hamburger had its origins in the seagoing practice of grinding tough, hard, salted beef to tenderize it, then mixing it with onions and soaked bread crumbs and frying it as patties or ersatz steaks. Many immigrants first encountered this dish on the Hamburg-American liners that brought so many of them to the U.S. in the late 19th century. When they landed in America, the newcomers kept their taste for this hamburger steak. In 1837, the first printed American menu was issued by New York's Delmonico's restaurant and listed, as one of its most expensive dishes, "hamburger steak." A French-German-English dictionary of food published in 1899 under the title Blueher's Rechtschreibung noted that "Chopped beefsteak is called hamburger steak in America." 2. ground beef.