From Longman Dictionary of Contemporary Englishdrawstringdraw‧string /ˈdrɔːstrɪŋ $ ˈdrɒː-/ noun [countable] DCCa string through the top of a bag, piece of clothing etc that you can pull to make it tighter trousers with a drawstring waist
Examples from the Corpus
drawstring• Check all zips and drawstrings are running smoothly before you set off camping.• Other features: elasticated drawstring at waist, elasticated ankle.• He crossed the street, carrying the book bag by its drawstrings, heading for the parked cop car.• He pulled out his tobacco pouch and pulled the drawstrings open.• Jane pulled on her trousers and tied the drawstring. 