Hungry retinues becoming unruly (8)
I believe the answer is:
esurient
'hungry' is the definition.
(similar in meaning)
'retinues becoming unruly' is the wordplay.
'becoming unruly' indicates an anagram.
'retinues' anagrammed gives 'ESURIENT'.
(Other definitions for esurient that I've seen before include "Hungry; retinues (anag.)" , "Greedy; ensure it (anag.)" , "Rapacious" , "could eat a horse" , "Hungry, greedy" .)