Collapsed round church part (4)
I believe the answer is:
apse
'church part' is the definition.
('apse' is part of 'church')
'collapsed round' is the wordplay.
'APSE' is hidden within the letters.
But, I'm unsure how this is indicated.
Can you help me to learn more?
(Other definitions for apse that I've seen before include "Rounded end of building" , "Church area" , "Peas (anag) - found in church" , "Semicircular recess in church" , "may be seen in church!" .)