A three-piece suit is a classic men's formalwear ensemble consisting of a jacket, VEST, and PANTS. The VEST, which is the crossword solution with four letters, is a sleeveless garment that is worn over the shirt and under the jacket. The PANTS, which is the crossword solution with five letters, are trousers that are usually made of the same material as the jacket. Together, these three pieces create a timeless look for any formal occasion.