Cauliflower relative (8)
I believe the answer is:
broccoli
'cauliflower relative' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for broccoli that I've seen before include "Vegetable with tightly packed green or purple flower heads" , "green veg" , "Vegetable in a strange cool crib" , "Vegetable with tight green flower heads" , "Sort of green cauli" .)