The following drink (6)
I believe the answer is:
chaser
'the following drink' is the definition.
'chaser' can be an answer for 'drink' (I've seen this before). I'm not certain of the 'the following' bit.
'following drink' is the wordplay.
'following' becomes 'chase' ('chase' can be a synonym of 'following').
'drink' becomes 'r' (I can't explain this - if you can you should give a lot more credence to this answer).
'chase'+'r'='CHASER'
Can you help me to learn more?
(Other definitions for chaser that I've seen before include "Huntsman" , "Milder drink taken after a stronger one" , "second drink" , "Drink following another of a different kind" , "Hunter; drink" .)