Fraud; falseness (6)
I believe the answer is:
deceit
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">fraud</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >'<span class="explanation-format__original">falseness</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ ></span>
(Other definitions for deceit that I've seen before include "Falsehood" , "Act of deliberate misleading" , "Cunning trickery" , "Hoodwinking" , "'Misrepresentation, deception (6)'" .)