in ‧ su ‧ pe ‧ ra ‧ ble /ɪnˈsjuːp ə rəb ə l◂ $ ɪnˈsuː-/ BrE AmE adjective formal
[ Date: 1300-1400 ; Language: French ; Origin: Latin , from superare 'to get over' , from super 'above' ]
an insuperable difficulty or problem is impossible to deal with:
There were insuperable obstacles, and the plan was abandoned.
As usual, the hero was facing insuperable odds.