Head for the drink (6)
I believe the answer is:
noggin
This clue is a double definition.
'head' is the first definition.
(noggin is a kind of head)
'the drink' is the second definition.
(drink measurement, typically a quarter of a pint)
'for' is the link.
(Other definitions for noggin that I've seen before include "Small measure of alcohol, about 1/4 pint" , "Gill usually" , "Head, noodle" , "Small quantity of spirits" , "spirited measure" .)