The Collaborative International Dictionary
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.
And middle natures, how they long to join,
Yet never pass the insuperable line?
--Pope.
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.
Wiktionary
adv. In an insuperable manner.
WordNet
adv. to an insuperable degree; "these various courses all seemed insuperably difficult to the student"
Usage examples of "insuperably".
Nevertheless, this difficulty, though appearing to our imagination insuperably great, cannot be considered real if we admit the following propositions, namely,--that gradations in the perfection of any organ or instinct, which we may consider, either do now exist or could have existed, each good of its kind,--that all organs and instincts are, in ever so slight a degree, variable,--and, lastly, that there is a struggle for existence leading to the preservation of each profitable deviation of structure or instinct.