Cry of the old town crier (4)
I believe the answer is:
oyez
'cry of the old town crier' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for oyez that I've seen before include "Town crier's utterance" , "Town crier's shout" , "Town crier's 'Attention!'" , "Call of public crier" , "Call of the olde Town Crier" .)