Part of church with intricate patterns (8)
I believe the answer is:
transept
'part of church' is the definition.
('transept' is part of 'church')
'intricate patterns' is the wordplay.
'intricate' is an anagram indicator.
'patterns' is an anagram of 'TRANSEPT'.
'with' is the link.
(Other definitions for transept that I've seen before include "always running north to south" , "Part of a church at right angles to the nave" , "Wing of cross-shaped church" , "Side part of a church" , "Crossing part of a church" .)