Confidence trick (4)
I believe the answer is:
scam
'confidence trick' is the definition.
(I know that confidence trick can be written as scam)
This is the entire clue.
(Other definitions for scam that I've seen before include "Fraud, trick (slang)" , "rook" , "ploy" , "Fraud, dishonest scheme" , "Swindle, fraud (colloq.)" .)