Clothes to boast about (4)
I believe the answer is:
garb
'clothes' is the definition.
(garb is a kind of clothes)
'boast about' is the wordplay.
'boast' becomes 'brag' (brag is a kind of boast).
'about' shows that the letters should be reversed in order.
'brag' backwards is 'GARB'.
'to' acts as a link.
(Other definitions for garb that I've seen before include "gear discovered" , "costume" , "Dress - clothing" , "Fashion of dress" , "Dress - habit" .)