Very popular old wine (4)
I believe the answer is:
vino
'wine' is the definition.
('vino' can be a synonym of 'wine')
'very popular old' is the wordplay.
'very' becomes 'v' (abbreviation).
'popular' becomes 'in'.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'v'+'in'+'o'='VINO'
(Other definitions for vino that I've seen before include "Italian wine - any brand" , "Wine (slang)" , "Italian or informal wine" , "Exotic wine" , "Cheap wine" .)