Heard victim beg (4)
I believe the answer is:
pray
'beg' is the definition.
(I've seen this before)
'heard victim' is the wordplay.
'heard' shows a homophone (sound like).
'victim' becomes 'prey' (prey is a kind of victim).
'prey' sounds like 'PRAY'.
(Other definitions for pray that I've seen before include "May I ask" , "Supplicate, petition" , "Devoutly hope" , "Hope strongly" , "Address a deity" .)