Source : Webster's Revised Unabridged Dictionary (1913)

Unfavorable \Un*fa"vor*a*ble\, a.
   Not favorable; not propitious; adverse; contrary;
   discouraging. -- {Un*fa"vor*a*ble*ness}, n. --
   {Un*fa"vor*a*bly}, adv.

Source : WordNet®

unfavorableness
     n : the quality of not being encouraging or indicative of
         success [syn: {unfavourableness}] [ant: {favorableness}]