Complete scam with hint about diamonds (8)
I believe the answer is:
conclude
'complete' is the definition.
(thesaurus)
'scam with hint about diamonds' is the wordplay.
I cannot quite see how this works, but
'scam' could be 'con' (I've seen this before) and 'con' is found within the answer.
'about' could be 'c' (abbreviation for circa) and 'c' is found in the answer.
'diamonds' could be 'd' (abbreviation for the card suit diamonds) and 'd' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for conclude that I've seen before include "Reach an opinion based on reasoning" , "reach verdict?" , "Bring or come to an end (8)" , "Infer or bring to an end" , "Finish - deduce" .)