A trench coat is a long, waterproof coat that is typically made from heavy-duty cotton or a blend of materials. Originally designed for military use during World War I, it features a double-breasted front, wide lapels, and a belted waist. The coat often has deep pockets and a vent at the back for ease of movement. Trench coats are popular in fashion and are worn by both men and women. They come in various colors, with classic shades like khaki and black being the most common. The coat is versatile, suitable for both casual and formal occasions, and is often associated with stylish characters in movies and literature.