Impudent talk about vegetable and fish (8)
I believe the answer is:
pilchard
'fish' is the definition.
(pilchard is a kind of fish)
'impudent talk about vegetable' is the wordplay.
'impudent talk' becomes 'lip' (informal term for impolite remarks).
'about' is a reversal indicator.
'vegetable' becomes 'chard' (chard is a kind of vegetable).
'lip' in reverse letter order is 'pil'.
'pil'+'chard'='PILCHARD'
'and' is the link.
(Other definitions for pilchard that I've seen before include "Item of seafood" , "'Small fatty fish, usually canned (8)'" , "Small sea fish related to the herring" , "Small fatty fish, usually tinned" , "Edible herring relative" .)