Toe-curling jewellery item found in church: value unknown (12)
I believe the answer is:
cringeworthy
'toe-curling' is the definition.
Both the definition and answer are adjectives.
Perhaps you can see a link between them that I don't see?
'jewellery item found in church value unknown' is the wordplay.
'jewellery item' becomes 'ring' (I've seen this before).
'found in' means one lot of letters goes inside another.
'church' becomes 'CE' (abbreviation for Church of England).
'value' becomes 'worth' (I've seen this in another clue).
'unknown' becomes 'y' (algebra).
'ring' going within 'ce' is 'cringe'.
'cringe'+'worth'+'y'='CRINGEWORTHY'
Can you help me to learn more?
(Other definitions for cringeworthy that I've seen before include "Causing embarrassment" , "Severely embarrassing" , "Acutely embarrassing" .)