Akademik

insuperable
I adjective beyond control, difficult, formidable, impassible, impervious, impossible, impracticable, impregnable, inaccessible, incapable of being overcome, incapable of being surmounted, indomitable, innavigable, insurmountable, invictus, invincible, invulnerable, out of reach, out of the question, unachievable, unassailable, unattackable, unattainable, unbeatable, unbridgeable, unconquerable, undefeatable, unfeasable, unmasterable, unobtainable, unovercomable II index impossible, impracticable, indomitable, inexpugnable, insurmountable, invincible, unattainable

Burton's Legal Thesaurus. . 2006