Takes head off those in 4 down and shreds the vegetables (8)
I believe the answer is:
parsnips
'the vegetables' is the definition.
(parsnip is a kind of vegetable)
'takes head off those in 4 down and shreds' is the wordplay.
I cannot quite understand how this works, but
'takes' could be 'nips' (I've seen this before) and 'nips' is located in the answer.
The remaining letters 'pars' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for parsnips that I've seen before include "not enhanced by fine words?" , "Veg" , "Spin spar around the vegetables" , "Things growing in garden" , "food" .)