fatburger noun2 •A hamburger made with extremely fatty meat.On meats, for example, stores can raise the real price simply by the way they trim, or by adding additional fat to hamburger. Especially watch out for fatburgers at this time. — 1971 •An extra-large hamburger.Liam finished off his fatburger in half a dozen big bites, mopped up the last of the juice with the last of the fries, and licked his fingers. — 1998 formsfatburgers
