Prudence holding a fine decanter (6)
I believe the answer is:
carafe
'decanter' is the definition.
(I know that decanter can be written as carafe)
'prudence holding a fine' is the wordplay.
'prudence' becomes 'care' (I've seen this in another clue).
'holding' is an insertion indicator.
'fine' becomes 'f' (abbreviation).
'a'+'f'='af'
'care' going around 'af' is 'CARAFE'.
(Other definitions for carafe that I've seen before include "Open-topped container for wine or water" , "Table container for wine" , "Wine is decanted into it" , "Wine, water, jug" , "Bottle with a stopper, for wine or water" .)