Way round permit for gambling game (8)
I believe the answer is:
roulette
'gambling game' is the definition.
(roulette is a kind of gambling game)
'way round permit' is the wordplay.
'way' becomes 'route' (route is a kind of way).
'round' means one lot of letters goes inside another.
'permit' becomes 'let' ('let' can be a synonym of 'permit').
'route' placed around 'let' is 'ROULETTE'.
'for' is the link.
(Other definitions for roulette that I've seen before include "Gambling game with small ball and revolving disc (8)" , "Gambling device" , "it's for the better, supposedly" , "Wheel for the gambler" , "If Russian, it's a very dangerous game" .)