Vegetable’s standard cut (7)
I believe the answer is:
parsnip
'vegetable's' is the definition.
(parsnip is a type of vegetable)
'standard cut' is the wordplay.
'standard' becomes 'par' (standard of play in golf).
'cut' becomes 'snip' (snipping is a kind of cutting).
'par'+'snip'='PARSNIP'
(Other definitions for parsnip that I've seen before include "Sweet root vegetable" , "Plant with edible white root" , "Pips ran oddly through the vegetable" , "Tapering vegetable" , "Type of root veg" .)