unchallengeable

adj

Etymology: Etymology tree Proto-Indo-European *né Proto-Indo-European *n̥- Proto-Germanic *un- Proto-West Germanic *un- Old English un- Middle English un- English un- English challengeable English unchallengeable From un- + challengeable.

1. Not open to challenge; indisputable

   “A century ago, a very distinguished Swiss military writer, who saw much service throughout the Napoleonic period, who studied minutely many of the principal campaigns, and who reflected profoundly upon international relations as affecting war, and as affected by it, stated as a fundamental necessity of the European Balance of Power that no one State should be permitted to acquire an unchallengeable naval superiority.”

   “With a solemn imprecation on the formality and absurdity of the writer, Lord Etherington let the letter of advice drop from his hand into the fire, and throwing himself into a chair, passed his hand across his eyes, as if their very power of sight bad been blighted by what he had read. His title, and his paternal fortune, which he thought but an instant before might be rendered unchallengeable by a single movement of his hand, seemed now on the verge of being lost for ever.”