After drink, fancy that card game (5)
I believe the answer is:
rummy
'card game' is the definition.
(I know that rummy is a type of card game)
'after drink fancy that' is the wordplay.
'after' says to put letters next to each other.
'drink' becomes 'rum' (rum is a kind of drink).
'fancy that' becomes 'my' (I can't explain this - if you can you should give a lot more credence to this answer).
'rum' next to 'my' is 'RUMMY'.
Can you help me to learn more?
(Other definitions for rummy that I've seen before include "Peculiar - card game" , "Odd; card-game" , "Card game; strange; like a spirit" , "with an alcoholic taste?" , "Set, sequence card game" .)