insuperable

adj

Etymology: From Latin insuperabilis.

1. Impossible to achieve or overcome or be negotiated.

   “Regular services for passengers and goods were maintained for almost 50 years, but the speed limit of 16 m.p.h., imposed by the Board of Trade, proved an insuperable handicap after the introduction of competitive motor bus services.”

   “While Indian English may not have a uniform standard form throughout the country, this in itself is not an insuperable obstacle for lexicography.”

2. Overwhelming or insurmountable.

   “For the first time I steadily reviewed the obstacles—and to consider them was at once to see they were insuperable.”