Bishop, getting fit, is shot in part of church (9)
I believe the answer is:
baptistry
'in part of church' is the definition.
(I've seen this before)
'bishop getting fit is shot' is the wordplay.
'bishop' becomes 'B' (chess abbreviation).
'getting fit' becomes 'apt' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'shot' becomes 'try' (both can mean an attempt).
'b'+'apt'+'is'+'try'='BAPTISTRY'
Can you help me to learn more?
(Another definition for baptistry that I've seen is " In part of church".)