1. That cannot be overcome or surmounted.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• inceperable,
• insperable,
• inspirable,
• insureable,
• insuferable,
• unseperable,
• insurrerable,
• inseperably,
• inserperable,
• inseperable,
• inopperable,
• insepperable,
• insuffrable,
• innoperable,
• inseprable,
• insuparable,
• insuprable,
• insuperabel,
• insupurable,
• insuperible

• inseparable,
• insuperably,
• insupportable,
• insufferable,
• inescapable.

The adjective form of "insuperable" is "insuperable".

The plural form of the word "insuperable" is "insuperables".

The singular form of the word "insuperable" is "insuperability"