Clamour for return of Fatty Arbuckle in small part (4)
I believe the answer is:
bray
'clamour' is the definition.
(both can mean to cry out or shout)
'return of fatty arbuckle in small part' is the wordplay.
'return of' says the letters should be written in reverse.
'in small part' indicates a hidden word (only part of the clue).
'yarb' is hidden in the letters of 'fatty arbuckle'.
'yarb' written backwards gives 'BRAY'.
'for' acts as a link.
(Other definitions for bray that I've seen before include "The Vicar of --; heehaw" , "time-serving cleric's place" , "Ass call" , "Sound asinine" , "renegade vicar's place" .)