A WAISTCOAT, also known as a VEST, is a part of a three-piece suit. It is a sleeveless garment that is worn over a dress shirt and under a coat. A VEST typically has buttons down the front and may be made from a variety of fabrics. PANTS are also a part of a three-piece suit and are trousers that are usually tailored to fit the wearer. They are typically made from wool or cotton and come in a variety of colors and styles. Both the WAISTCOAT and PANTS are essential components of a three-piece suit.