Not varying; clothing (7)
I believe the answer is:
uniform
This clue is a double definition.
'not varying' is the first definition.
(I've seen this before)
'clothing' is the second definition.
(I know that uniform is a type of clothing)
(Other definitions for uniform that I've seen before include "Services' clothing" , "Identifying clothing" , "follower of tango on the radio?" , "Regular - distinctive garb" , "Homogeneous" .)