Source : Webster's Revised Unabridged Dictionary (1913)

Favorable \Fa"vor*a*ble\, a. [Written also {favourable}.] [F.
   favorable, L. favorabilis favored, popular, pleasing, fr.
   favor. See {Favor}, n.]
   1. Full of favor; favoring; manifesting partiality; kind;
      propitious; friendly.

            Lend favorable ears to our request.   --Shak.

            Lord, thou hast been favorable unto thy land. --Ps.
                                                  lxxxv. 1.

   2. Conducive; contributing; tending to promote or facilitate;
      advantageous; convenient.

            A place very favorable for the making levies of men.
                                                  --Clarendon.

            The temper of the climate, favorable to generation,
            health, and long life.                --Sir W.
                                                  Temple.

   3. Beautiful; well-favored. [Obs.] --Spenser. --
      {Fa"vora*ble*ness}, n. -- {Fa"vor*a*bly}, sdv.

            The faborableness of the present times to all
            extertions in the cause of liberty.   --Burke.

Source : WordNet®

favorableness
     n : the quality of being encouraging or promising of a
         successful outcome [syn: {favourableness}, {advantageousness}]
         [ant: {unfavorableness}]