Part with ground product bit by bit (9)
I believe the answer is:
piecemeal
'bit by bit' is the definition.
(synonyms)
'part with ground product' is the wordplay.
'part' becomes 'piece' (piece is a kind of part).
'with' is a charade indicator (letters next to each other).
'ground product' becomes 'meal' (I can't explain this - if you can you should give a lot more credence to this answer).
'piece'+'meal'='PIECEMEAL'
Can you help me to learn more?
(Other definitions for piecemeal that I've seen before include "Unsystematically" , "Bit by bit; unsystematic" , "A bit at a time" , "step by step" , "taken bit by bit" .)