A sin that's approved (6)
I believe the answer is:
agreed
'approved' is the definition.
Both the answer and definition are adjectives. Perhaps they are linked in a way I don't understand?
'a sin' is the wordplay.
'sin' becomes 'greed' (greed is a kind of sin).
'a'+'greed'='AGREED'
'that's' acts as a link.
Can you help me to learn more?
(Other definitions for agreed that I've seen before include "Jointly decided" , "Acquiesed, concurred" , "Let's do it!" , "came to the same conclusion" , "Did concur" .)