Real Dictionary

red meat
variable noun: Red meat is meat such as beef or lamb, which is dark brown in colour after it has been cooked.

red meat in American English
meat that is red before cooking; esp., beef or mutton as distinguished from pork, veal, poultry, etc.
noun: any meat that is dark-colored before cooking, as beef, lamb, venison, or mutton (distinguished from white meat)

red meat in British English
noun: any meat that is dark in colour, esp beef and lamb