Part of a church in a state of collapse (4)
I believe the answer is:
apse
'part of a church' is the definition.
('apse' is part of 'church')
'a state of collapse' is the wordplay.
'APSE' is hidden in amongst the letters.
However, I am unsure how the hidden word is indicated.
'in' is the link.
Can you help me to learn more?
(Other definitions for apse that I've seen before include "Rounded end of building" , "Niche in church" , "In sacred space" , "Church recess with domed or arched roof" , "Peas (anag) - found in church" .)