The Collaborative International Dictionary of English v.0.48:

Impiety \Im*pi"e*ty\ ([i^]m*p[imac]"[-e]*t[y^]), n.; pl.
   Impieties ([i^]m*p[imac]"[-e]*t[i^]z). [L. impietas, fr.
   impius impious; cf. F. impi['e]t['e]. See Impious,
   Piety.]
   1. The quality of being impious; lack of piety; irreverence
      toward the Supreme Being; ungodliness; wickedness.
      [1913 Webster]

   2. An impious act; an act of wickedness.
      [1913 Webster]

            Those impieties for the which they are now visited.
                                                  --Shak.

   Syn: Ungodliness; irreligion; unrighteousness; sinfulness;
        profaneness; wickedness; godlessness.
        [1913 Webster]