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