Clothing, apparel (6)
I believe the answer is:
I believe this clue is a double definition.
'clothing' is the first definition.
(I know that clothing can be written as attire)
'apparel' is the second definition.
(I know that apparel can be written as attire)
(Other definitions for attire that I've seen before include "(To) dress; fine clothes" , "Fine/formal clothes" , "Clothes worn" , "12" , "Formal clothes" .)