The Collaborative International Dictionary of English v.0.48:

Obediential \O*be`di*en"tial\, a. [Cf. F. ob['e]dientiel.]
   According to the rule of obedience. [R.]
   [1913 Webster]

         An obediental subjection to the Lord of Nature. --Sir
                                                  M. Hale.
   [1913 Webster]