Duplicity, dishonesty (6)
I believe the answer is:
deceit
This clue is a double definition.
'duplicity' is the first definition.
(I've seen this in another clue)
'dishonesty' is the second definition.
(deceit is a kind of dishonesty)
(Other definitions for deceit that I've seen before include "Dishonest trick" , "Chicanery" , "Hypocrisy" , "Dishonesty, misrepresentation" , "Hoodwinking" .)