Source : Webster's Revised Unabridged Dictionary (1913)

Superable \Su"per*a*ble\, a. [L. superabilis, from superare to
   go over, to surmount, fr. super above, over.]
   Capable of being overcome or conquered; surmountable.

         Antipathies are generally superable by a single effort.
                                                  --Johnson.
   -- {Su"per*a*ble*ness}, n. -- {Su"per*a*bly}, adv.

Source : WordNet®

superable
     adj : capable of being surmounted or excelled [syn: {conquerable}]