Colic Rob gets shifting cabbage (8)
I believe the answer is:
broccoli
'cabbage' is the definition.
(broccoli is a plant of the cabbage family)
'colic rob gets shifting' is the wordplay.
'gets shifting' indicates an anagram.
'colic'+'rob'='colicrob'
'colicrob' with letters rearranged gives 'BROCCOLI'.
(Other definitions for broccoli that I've seen before include "Type of cabbage" , "Calabrese" , "Green vegetable - producer of Bond films" , "Vegetable in a strange cool crib" , "Vegetable with tightly packed green or purple flower heads" .)