Insuperable (adjective)

1. Incapable of being overcome, surmounted, or solved.
2. Impossible to overcome or deal with effectively.

Origin:

Late latin insuperabilis, from latin in- + superabilis capable of being overcome, from superare to overcome.

Examples:

1. The obstacles he faced seemed insuperable, but he refused to give up.
2. The insuperable odds against them did not deter their determination.
3. Despite the insuperable challenges, they persevered and succeeded.
4. The insuperable problem with the plan was its cost.
5. The team faced insuperable difficulties and was forced to withdraw from the competition.