Definition of bum bag in English English dictionary
A small pouch attached to a belt that is worn on the outside of clothing around the waist and used for holding small personal items
She wears her bum bag every day on her morning jog around Hyde Park.
A bum bag consists of a small bag attached to a belt which you wear round your waist. You use it to carry things such as money and keys. a small bag that you wear around your waist to hold money, keys etc
(British) fanny pack, small pouch that is fastened around the waist with a belt-like strap