Ring cleric, upset (6)
I believe the answer is:
circle
'ring' is the definition.
('circle' can be a synonym of 'ring')
'cleric upset' is the wordplay.
'upset' indicates anagramming the letters.
'cleric' anagrammed gives 'CIRCLE'.
(Other definitions for circle that I've seen before include "Perfect round" , "Section of theatre; group of friends" , "Move around (something)" , "Clique; loop" , "Upper theatre seating" .)