Rogue quietly abandoned swindle (4)
I believe the answer is:
scam
'swindle' is the definition.
(scam is a kind of swindle)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for scam that I've seen before include "Swindle (sl.)" , "Fraudulent action" , "Fraud, dishonest scheme" , "Hoax" , "Rip-off" .)