Something shady (4)
I believe the answer is:
scam
'something shady' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for scam that I've seen before include "Fraudulent scheme, swindle" , "Con trick" , "Swindle (Slang)" , "Fraud, trick (slang)" , "Dubious operation" .)