From Longman Dictionary of Contemporary Englishwaistbandwaist‧band /ˈweɪstbænd/ noun [countable] DCCthe part of a skirt, trousers etc that fastens around your waist
Examples from the Corpus
waistband• Made from 100% nylon these trousers have an elasticated & tie-cord waistband + stirrup legs.• Other features: semi-elasticated waistband with belt loops.• She tugged at her skirt and adjusted her waistband.• Feeling an itch under her waistband, Fourth Aunt reached down and plucked out something fat and meaty.• Runnels of sweat darkened the front of his white shirt and spread in a line along his waistband.• In the gap between the brassière and the pinched waistband of her skirt, her flesh bulged in a pale soft band.• Fashionable lacing on the waistband of these trousers helps to accentuate a trim figure.• Roll up the waistband like a belt and the pleats will roll into one another. 