Mystery meat is a disparaging term for ground meat products such as döner kebabs, Spam, Salisbury steaks, or any similarly prepared ground meat patty that comprises the main course of an American public school lunch, often served with gravy. This type of meat acquired the name because it is often difficult to identify its primary ingredient.
The term mystery meat is sometimes applied to meat products where the species from which the meat has come is known (e.g., cow or pig), but the cuts of meat (i.e., the parts of the animal) used are unknown. This is often the case where the cuts of meat used include offal and mechanically recovered meat, where explicitly stating the meat used might diminish the palatability of the product to some consumers. Examples include Spam, hot dogs, bologna sausage, and chorizo.