Odd patterns seen in part of church (8)
I believe the answer is:
transept
'part of church' is the definition.
(I know this)
'odd patterns' is the wordplay.
'odd' indicates an anagram.
'patterns' is an anagram of 'TRANSEPT'.
'seen in' acts as a link.
(Other definitions for transept that I've seen before include "Something dividing church in two" , "Wing of cross-shaped church" , "always running north to south" , "Arm of church body" , "Side part of a church" .)