Greedy retinues run amok (8)
I believe the answer is:
esurient
'greedy' is the definition.
(I know that greedy can be written as esurient)
'retinues run amok' is the wordplay.
'run amok' indicates an anagram.
'retinues' is an anagram of 'ESURIENT'.
(Other definitions for esurient that I've seen before include "Hungry; retinues (anag.)" , "Rapacious" , "Hungry, greedy" , "Greedy; ensure it (anag.)" , "could eat a horse" .)