Illegal operation (4)
I believe the answer is:
scam
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">illegal operation</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for scam that I've seen before include "Fraudulent trick or swindle" , "Fraud, trick (slang)" , "A slangy swindle or fraud" , "Fraud, dishonest scheme" , "fiddle" .)