Hit back and prune plant (7)
I believe the answer is:
parsnip
'plant' is the definition.
(parsnip is a kind of plant)
'hit back and prune' is the wordplay.
'hit' becomes 'rap' (I've seen this in other clues**).
'back' says the letters should be written in reverse.
'and' is a charade indicator (letters next to each other).
'prune' becomes 'snip' ('snip' can be a synonym of 'prune').
'rap' reversed gives 'par'.
'par'+'snip'='PARSNIP'
(Other definitions for parsnip that I've seen before include "Sweet root vegetable" , "Type of root veg" , "Pips ran oddly through the vegetable" , "Yellow root vegetable" , "food" .)