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]