Come to finger gangster (5)
I believe the answer is:
total
'come to' is the definition.
('total' can be a synonym of 'come to')
'finger gangster' is the wordplay.
'finger' becomes 'tot' (both are a small amount of alcohol).
'gangster' becomes 'al' (Al Capone).
'tot'+'al'='TOTAL'
(Other definitions for total that I've seen before include "Sum, aggregation" , "final answer" , "Full, entire amount" , "Entire sum" , "Comprising the whole" .)