improvable
    adj 1: susceptible of improvement

Improvable \Im*prov"a*ble\, a. [From Improve.]
   1. Capable of being improved; susceptible of improvement;
      admitting of being made better; capable of cultivation, or
      of being advanced in good qualities.
      [1913 Webster]

            Man is accommodated with moral principles,
            improvable by the exercise of his faculties. --Sir
                                                  M. Hale.
      [1913 Webster]

            I have a fine spread of improvable lands. --Addison.
      [1913 Webster]

   2. Capable of being used to advantage; profitable;
      serviceable; advantageous.
      [1913 Webster]

            The essays of weaker heads afford improvable hints
            to better.                            --Sir T.
                                                  Browne.
      -- Im*pro"a*ble*ness, n. -- Im*prov"a*bly, adv.
      [1913 Webster]