Source : Webster's Revised Unabridged Dictionary (1913)

Dupe \Dupe\, v. t. [imp. & p. p. {Duped}; p. pr. & vb. n.
   {Duping}.] [Cf. F. duper, fr. dupe. See {Dupe}, n.]
   To deceive; to trick; to mislead by imposing on one's
   credulity; to gull; as, dupe one by flattery.

         Ne'er have I duped him with base counterfeits. --
                                                  Coleridge.

Dupe \Dupe\, n. [F., prob. from Prov. F. dupe, dube; of unknown
   origin; equiv. to F. huppe hoopoe, a foolish bird, easily
   caught. Cf. Armor. houp['e]rik hoopoe, a man easily deceived.
   Cf. also {Gull}, {Booby}.]
   One who has been deceived or who is easily deceived; a gull;
   as, the dupe of a schemer.

Source : WordNet®

dupe
     v : fool or hoax; "The immigrant was duped because he trusted
         everyone"; "You can't fool me!" [syn: {gull}, {slang}, {befool},
          {cod}, {fool}, {put on}, {take in}, {put one over}, {put
         one across}]

dupe
     n : a person who is tricked or swindled [syn: {victim}]