Improvised fashion garment (9)
I believe the answer is:
makeshift
'improvised' is the definition.
(I know that improvised can be written as makeshift)
'fashion garment' is the wordplay.
'fashion' becomes 'make' (fashion can mean to make or create).
'garment' becomes 'shift' (shift is a kind of garment).
'make'+'shift'='MAKESHIFT'
(Other definitions for makeshift that I've seen before include "stopgap" , "this'll do for now" , "What 11 [SEAMSTRESS] might do" , "Provisional" , "Temporary or improvised substitute" .)