A duffel bag is a bag shaped like a cylinder and made of strong fabric such as canvas. A duffel bag has a string at one end that is used to close the bag and to carry it with.
duffel bag in British English
noun
a cylindrical drawstring canvas bag, originally used esp by sailors for carrying personal articles
duffel bag in American English
duffle bag
US
a large, cylindrical cloth bag, esp. of waterproof canvas or duck, for carrying clothing and personal belongings