Drinker's snack? (6)
I believe the answer is:
supper
This clue is a double definition.
'drinker's' is the first definition.
(someone who 'sups')
'snack?' is the second definition.
(Other definitions for supper that I've seen before include "Last meal of the day" , "Light evening meal" , "Light, late, meal" , "has one had a few drinks?" , "Evening repast" .)