(ˈ)in, ən+ adjective
Etymology: Middle English, from Middle French & Latin; Middle French, from Latin insuperabilis, from in- in- (I) + superabilis superable — more at superable
: incapable of being surmounted: as
a. : incapable of being vanquished : invincible
these insuperable heroes who dared the northern seas
b. : impossible to overcome
insuperable difficulties
c. : incapable of being passed over : impassable
an insuperable barrier
d. : unsurpassable
• in·su·per·a·ble·ness -nə̇s noun
• in·su·per·a·bly -blē, -bli adverb