A drink before my game (5)
I believe the answer is:
rummy
'game' is the definition.
(I know that rummy is a type of card game)
'a drink before my' is the wordplay.
'a drink' becomes 'rum' (rum is a kind of drink).
'before' is a charade indicator (letters next to each other).
'rum'+'my'='RUMMY'
(Other definitions for rummy that I've seen before include "game of cards" , "Gin perhaps?" , "Odd; card-game" , "Card game; strange; like a spirit" , "Peculiar - card game" .)