Mutton is meat from an adult sheep, usually at least two years old. While lamb comes from young sheep and has a mild, tender flavor, mutton comes from older animals and tastes stronger and richer. The meat is darker and firmer than lamb, with a distinctive flavor that some people love and others find too intense.

For most of human history, mutton was extremely common on dinner tables. Farmers kept sheep primarily for their wool, and when the animals got too old to produce good wool, they became food. In old books like Treasure Island or tales of medieval feasts, characters often eat mutton. Today, mutton is less popular in America but remains an important food in many countries, especially in the Middle East, South Asia, and parts of Europe and Africa, where cooks have perfected ways to prepare it with spices and slow cooking methods that make the meat tender and flavorful.

The phrase mutton dressed as lamb refers to someone trying to appear younger than they are, comparing mutton pretending to be lamb.