Very good pickle (5)
I believe the answer is:
souse
'pickle' is the definition.
(I've seen this in another clue)
'very good' is the wordplay.
'very' becomes 'so' (both can mean 'extremely').
'good' becomes 'use' (in phrases like 'it's no good', 'any good?' etc).
'so'+'use'='SOUSE'
(Other definitions for souse that I've seen before include "Drench" , "Wash" , "Pickle - drunkard" , "thoroughly wet" , "Duck" .)