Cower when a jewellery item is found in church
I believe the answer is:
cringe
'cower' is the definition.
(synonyms)
'a jewellery item is found in church' is the wordplay.
'a jewellery item' becomes 'ring' (I've seen this before).
'is found in' is an insertion indicator.
'church' becomes 'CE' (abbreviation for Church of England).
'ring' put within 'ce' is 'CRINGE'.
'when' acts as a link.
(Other definitions for cringe that I've seen before include "Cower in embarrassment or fear" , "obeisance" , "Shrink back, cower" , "Grovel" , "Recoil in embarrassment" .)