Clear off without right racket (4)
I believe the answer is:
scam
'racket' is the definition.
(racket is a type of scam or scheme)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for scam that I've seen before include "Fraudulent trick or swindle" , "Fraudulent business scheme" , "A slangy swindle or fraud" , "Dodgy business" , "ploy" .)