Report on key part of church (5)
I believe the answer is:
aisle
This might be a double definition.
'report on key' is the first definition.
'aisle' can be an answer for 'key' (I have seen 'A key' mean 'aisle' so perhaps 'key' could also mean 'aisle'). I'm unsure of the 'report on' bit.
'part of church' is the second definition.
(I've seen this before)
Can you help me to learn more?
(Other definitions for aisle that I've seen before include "Passage between seating areas" , "'Passage, gangway (5)'" , "Passage between rows of seats" , "Passageway between pews" , "Walkway between seats" .)