The Collaborative International Dictionary of English v.0.48:

Miscreance \Mis"cre*ance\, Miscreancy \Mis"cre*an*cy\, n. [OF.
   mescreance, F. m['e]cr['e]ance incredulity.]
   The quality of being miscreant; adherence to a false
   religion; false faith. [Obs.] --Ayliffe.
   [1913 Webster]