Source : Webster's Revised Unabridged Dictionary (1913)

Insincerity \In`sin*cer"i*ty\, n. [Cf. F. insinc['e]rit['e].]
   The quality of being insincere; want of sincerity, or of
   being in reality what one appears to be; dissimulation;
   hypocritical; deceitfulness; hollowness; untrustworthiness;
   as, the insincerity of a professed friend; the insincerity of
   professions of regard.

         What men call policy and knowledge of the world, is
         commonly no other thing than dissimulation and
         insincerity.                             --Blair.

Source : WordNet®

insincerity
     n : the quality of not being open or truthful; deceitful or
         hypocritical [syn: {falseness}] [ant: {sincerity}]