Unvarying outfit (7)
I believe the answer is:
uniform
This clue is a double definition.
'unvarying' is the first definition.
(I've seen this before)
'outfit' is the second definition.
(thesaurus)
(Other definitions for uniform that I've seen before include "The clothing is always the same," , "Dress of distinctive design worn by members of a group" , "Outfit; consistent" , "Evening" , "Distinctive outfit" .)