Scoundrel heard in part of church (4)
I believe the answer is:
nave
'part of church' is the definition.
(I know that nave part of church)
'scoundrel heard' is the wordplay.
'scoundrel' becomes 'knave' (knave is a kind of scoundrel).
'heard' shows a homophone (sound like).
'knave' sounds like 'NAVE'.
'in' acts as a link.
(Other definitions for nave that I've seen before include "Take no risks" , "Main part of a church" , "Middle of wheel" , "Central space in church" , "Part of the church sounds like a rogue" .)