The phrase "to fit the waist" means that something, like clothing or a belt, is the right size and shape to comfortably go around a person's waist, without being too tight or too loose. Full definition
The waistband adjusts to fit a waist size from 26 to 52 inches. (thetoddle.com)
Perfect for special occasions, it features a pretty embroidered lace overlay and a flattering fitted waist for a feminine silhouette. (debenhams.ie)
These large dog diapers from Four Paws come with its own brand of a superior - fitting Flex - Fit waist band complete with a tail opening for greater comfort for your pooch. (mypetneedsthat.com)