Narrowing middles, also known as waist training, is a process of using corsets or other body-shaping garments to reduce the size of the waist. This practice has been around for centuries and is still popular today. Waists, the 6 letter solution to this crossword, is a term used to describe the area between the rib cage and hips. Waist training is a way to achieve an hourglass figure by reducing the size of the waist and accentuating the curves of the body.