One piece of land that may belong to the church (5)

I believe the answer is:
aisle
'land that may belong to the church' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'one piece' is the wordplay.
'one' becomes 'a' (a thing is one thing).
'piece' becomes 'isle' (I have seen 'Piece of land' mean 'isle' so perhaps 'piece' could also mean 'isle').
'a'+'isle'='AISLE'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for aisle that I've seen before include "The way to get married in church?" , "Way between seat blocks" , "Passageway in theatre" , "Walkway between seats" , "Passage between seating areas" .)
