Intricate patterns in part of church (8)
I believe the answer is:
transept
'part of church' is the definition.
('transept' is part of 'church')
'intricate patterns' is the wordplay.
'intricate' indicates anagramming the letters.
'patterns' anagrammed gives 'TRANSEPT'.
'in' is the link.
(Other definitions for transept that I've seen before include "Section of church" , "It crosses the nave in church" , "Part of a church - patterns (anag)" , "Patterns in part of church at right angle to nave" , "Patterns found in parts of church" .)