Source : Webster's Revised Unabridged Dictionary (1913)

Imperfection \Im`per*fec"tion\, n. [L. imperfectio: cf. F.
   imperfection. See {Imperfect}, a.]
   The quality or condition of being imperfect; want of
   perfection; incompleteness; deficiency; fault or blemish.

         Sent to my account With all my imperfections on my
         head.                                    --Shak.

   Syn: Defect; deficiency; incompleteness; fault; failing;
        weakness; frailty; foible; blemish; vice.

Source : WordNet®

imperfection
     n : the state or an instance of being imperfect [syn: {imperfectness}]
         [ant: {perfection}]