The term 'OLD CARBINE' can be broken down into two crossword solutions: STEN (4 letters) and OLD (3 letters). The STEN solution is a reference to the British submachine gun developed during World War II. It was a simple, inexpensive weapon that was easy to manufacture and use. The OLD solution refers to the age of the carbine, which is a type of rifle. Carbines were originally developed in the 19th century and have been used by militaries around the world for many years.