What is a "greatcoat"?

A greatcoat is a type of long, heavy overcoat traditionally worn by military officers in cold and wet weather. It is typically made from a heavy wool or wool blend fabric and features a double-breasted front, large lapels, and often has epaulets on the shoulders. Greatcoats are designed to provide warmth and protection from the elements, and they often have a full-length skirt that extends to the ankles or below. They can also have a detachable lining for added warmth or versatility. In addition to military use, greatcoats have been popular among civilians as a stylish and functional winter coat.