Longman Dictionary of Contemporary English
bum bag
noun
EXAMPLES FROM CORPUS
▪ She wore a yellow taffeta ball gown with black pumps and matching bum bag for her liver treats!
Wiktionary
bum bag
n. (context British Australia New Zealand English) 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.
Usage examples of "bum bag".
He measured the unexcited voices, then slowly, carefully unhooked the bum bag, unzipped it, took out the screwdriver and the roll of duct tape.