A church body (4)
I believe the answer is:
nave
'a church body' is the definition.
(part of a church building)
This is the entire clue.
(Other definitions for nave that I've seen before include "Main part of a church" , "Middle of wheel" , "Part of a church sounds roguish" , "Part of the church sounds like a rogue" , "Main body of a church" .)