Clothing minus uniform for travelling incognito initially (5)
I believe the answer is:
mufti
'clothing' is the definition.
(mufti is a kind of clothing)
'minus uniform for travelling incognito initially' is the wordplay.
'initially' indicates taking the first letters.
The first letters of 'minus uniform for travelling incognito' is 'MUFTI'.
(Other definitions for mufti that I've seen before include "officer of the law" , "Civilian gear" , "No official dress" , "Plain clothes - Muslim legal expert" , "Civilian clothing; Muslim legal expert" .)