Scrag end is the name of a cut of lamb and mutton, common in the UK and the Commonwealth. It is a primal cut, thus is separated from the carcass during butcher

Butcher

A butcher is a person who may slaughter animals, dress their flesh, sell their meat or any combination of these three tasks. They may prepare standard cuts of meat, poultry, fish and shellfish for sale in retail or wholesale food establishments...

ing. It is one of the cheaper cuts of meat, and can be used in soups and stew

Stew

A stew is a combination of solid food ingredients that have been cooked in liquid and served in the resultant gravy. Ingredients in a stew can include any combination of vegetables , meat, especially tougher meats suitable for slow-cooking, such as beef. Poultry, sausages, and seafood are also used...

s.
Scrag end is also like the neck in the US. It is near the front of the lamb and sometimes referred to as the shoulder.