Bagpiper's garment (4)
I believe the answer is:
kilt
'bagpiper's garment' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for kilt that I've seen before include "Scotsman's garment" , "Scotsman's garb" , "Scottish costume" , "Bone; circle line" , "Highland garment" .)