The Collaborative International Dictionary of English v.0.48:

Conation \Co*na"tion\, n. [L. conatio.] (Philos.)
   The power or act which directs or impels to effort of any
   kind, whether muscular or psychical.
   [1913 Webster]

         Of conation, in other words, of desire and will. --J.
                                                  S. Mill.
   [1913 Webster]