What is a "topcoat"?

A topcoat is typically made of heavy wool or a wool-blend material and is designed to be worn over a suit or other formal attire. It is longer than a traditional coat, typically falling just below the knee, and is often single-breasted with a notched lapel. The topcoat is typically a more formal garment than a traditional winter coat and is designed to be worn during colder weather to provide additional warmth and protection from the elements while still maintaining a sophisticated and elegant appearance.