Attaches blame when returning veg (7)
I believe the answer is:
parsnip
'veg' is the definition.
(I know that parsnip is a type of Root Vegetable)
'attaches blame when returning' is the wordplay.
'attaches' becomes 'pins' (pinning is a kind of attaching).
'blame' becomes 'rap' (synonyms).
'when returning' shows that the letters should be reversed in order.
'pins'+'rap'='pinsrap'
'pinsrap' back-to-front is 'PARSNIP'.
(Other definitions for parsnip that I've seen before include "Pale carrot-like vegetable" , "A white root vegetable" , "Spar pin (anag) - vegetable" , "Sweet root vegetable" , "Type of root veg" .)