Dress alike (7)
I believe the answer is:
uniform
This clue is a double definition.
'dress' is the first definition.
(I know that uniform is a type of dress)
'alike' is the second definition.
(I've seen this before)
(Other definitions for uniform that I've seen before include "Distinctive outfit" , "Regular - soldier's dress" , "Identifying clothing" , "The clothing is always the same," , "Alike all over" .)