Civilian garb (5)
I believe the answer is:
mufti
'civilian garb' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for mufti that I've seen before include "For soldiers, civilian dress" , "Soldier's civilian clothes" , "Civilian clothing for a military person" , "Non-military clothing" , "Civilian attire" .)