Source : Webster's Revised Unabridged Dictionary (1913)

Dupery \Dup"er*y\, n. [F. duperie, fr. duper.]
   The act or practice of duping. [R.]

Source : WordNet®

dupery
     n : something intended to deceive; deliberate trickery intended
         to gain an advantage [syn: {fraud}, {fraudulence}, {hoax},
          {humbug}, {put-on}]