The Collaborative International Dictionary of English v.0.48:

Dishonesty \Dis*hon"es*ty\, n. [Cf. OF. deshonest['e], F.
   d['e]shonn[^e]tet['e].]
   1. Dishonor; dishonorableness; shame. [Obs.] "The hidden
      things of dishonesty." --2 Cor. iv. 2.
      [1913 Webster]

   2. Want of honesty, probity, or integrity in principle; want
      of fairness and straightforwardness; a disposition to
      defraud, deceive, or betray; faithlessness.
      [1913 Webster]

   3. Violation of trust or of justice; fraud; any deviation
      from probity; a dishonest act.
      [1913 Webster]

   4. Lewdness; unchastity. --Shak.
      [1913 Webster]

WordNet (r) 3.0 (2006):

dishonesty
    n 1: the quality of being dishonest [ant: honestness,
         honesty]
    2: lack of honesty; acts of lying or cheating or stealing [syn:
       dishonesty, knavery]

Moby Thesaurus II by Grady Ward, 1.0:

80 Moby Thesaurus words for "dishonesty":
   Machiavellianism, ambidexterity, artifice, bad faith,
   ballot-box stuffing, bunco, cardsharping, cheat, cheating, chicane,
   chicanery, corruptedness, corruption, corruptness, cozenage,
   credibility gap, criminality, crookedness, cunning, deceitfulness,
   deviousness, diddle, diddling, dishonor, dodge, double-dealing,
   doubleness, doubleness of heart, duplicity, evasiveness,
   faithlessness, falseheartedness, falsehood, falseness,
   feloniousness, fibbery, fibbing, fishy transaction, flam, flimflam,
   fraud, fraudulence, fraudulency, gerrymandering, graft, grift, gyp,
   gyp joint, hanky-panky, illicit business, imposition, imposture,
   improbity, indirection, low cunning, lying, mendaciousness,
   mendacity, mythomania, pseudology, racket, scam, shadiness,
   sharp practice, shiftiness, slipperiness, swindle, treachery,
   trickery, trickiness, truthlessness, two-facedness,
   unconscientiousness, underhandedness, unsavoriness,
   unscrupulousness, unstraightforwardness, untruthfulness,
   unveraciousness, wile