Part of church that may be divided into ten parts (8)
I believe the answer is:
transept
'part of church' is the definition.
('transept' is part of 'church')
'may be divided into ten parts' is the wordplay.
'ten parts' anagrams to 'TRANSEPT'.
But, I'm not sure how the anagram is indicated.
'that' acts as a link.
Can you help me to learn more?
(Other definitions for transept that I've seen before include "Crossing part of a church" , "Part of church intersecting nave" , "Section of church" , "Cross-aisle in church" , "It crosses the nave in church" .)