The Collaborative International Dictionary of English v.0.48:

Facinorous \Fa*cin"o*rous\, a. [L. facinorous, from facinus
   deed, bad deed, from facere to make, do.]
   Atrociously wicked. [Obs.] --Jer. Taylor. --
   Fa*cin"o*rous*ness, n. [Obs.]
   [1913 Webster]