The Collaborative International Dictionary of English v.0.48:

Propension \Pro*pen"sion\, n. [L. propensio: cf. F. propension.
   See Propend, Propense.]
   The quality or state of being propense; propensity. --M.
   Arnold.
   [1913 Webster]

         Your full consent
         Gave wings to my propension.             --Shak.
   [1913 Webster]