Clothes worn back-to-front for game (4)
I believe the answer is:
brag
'for game' is the definition.
(I've seen this before)
'clothes worn back-to-front' is the wordplay.
'clothes' becomes 'garb' (garb is a kind of clothes).
'worn back-to-front' says the letters should be written in reverse.
'garb' in reverse letter order is 'BRAG'.
(Other definitions for brag that I've seen before include "Talk boastfully" , "Boast ? card-game" , "boast; form of poker" , "Card game, like poker" , "Show off, crow" .)