Here's fine wine — no good abstaining! (7)
I believe the answer is:
fasting
'abstaining' is the definition.
(fasting is abstaining from food)
'here's fine wine no good' is the wordplay.
'here's fine' becomes 'f' (I can't explain this - if you can you should give a lot more credence to this answer).
'wine' becomes 'asti' (Italian wine).
'no good' becomes 'ng' (abbreviation for no and good).
'f'+'asti'+'ng'='FASTING'
(Other definitions for fasting that I've seen before include "not eating" , "Going without food" .)