Other forms: burgers
A grilled beef patty on a bun is called a burger. Lunch at a fast food restaurant often consists of a burger and fries.
You can use the word burger as a casual shorthand for hamburger, which is ground or minced beef that's fried and served on a bun. A burger can also be made of other ingredients, like turkey or tofu or lamb. In fact, if you shape food into a patty, grill it, and put it on a roll or bun, you can call it a burger. The word was first used in 1939, from hamburger.