Broad line curls round belt (9)
I believe the answer is:
bandolier
'round belt' is the definition.
(belt carrying ammunition or rounds)
'broad line curls' is the wordplay.
'curls' indicates an anagram (I've seen 'curling' mean this (letters curl and twist out of order)).
'broad'+'line'='broadline'
'broadline' with letters rearranged gives 'BANDOLIER'.
(Other definitions for bandolier that I've seen before include "Shoulder belt for cartridges" , "Round belt" , "Ammunition belt" , "Gun cartridge belt" , "Shoulder belt for carrying bullets" .)