insuperably

from WordNet (r) 3.0 (2006)

insuperably
    adv 1: to an insuperable degree; "these various courses all
           seemed insuperably difficult to the student"

from The Collaborative International Dictionary of English v.0.48

Insuperable \In*su"per*a*ble\, a. [L. insuperabilis: cf. OF.
   insuperable. See {In-} not, and {Superable}.]
   Incapable of being passed over or surmounted; insurmountable;
   as, insuperable difficulties.
   [1913 Webster]

         And middle natures, how they long to join,
         Yet never pass the insuperable line?     --Pope.
   [1913 Webster]

         The difficulty is enhanced, or is . . . insuperable.
                                                  --I. Taylor.

   Syn: Impassable; insurmountable; unconquerable. --
        {In*su"per*a*ble*ness}, n. -- {In*su"per*a*bly}, adv.
        [1913 Webster]