impregnable

In our own single manhood to be bold, Fortressed in conscience and impregnable.'

Slowly, cautiously, it was unrolling its ball of impregnable armour.

The Republic could not suffer at their hands; the Republic and the dynasty were impregnable.

General von Kluck's artillery was impregnable to the French.

That was, indeed, an impregnable position for any one who knew how to defend it.

It is an impregnable fortress which nothing can ever break down.

It were odd if I did not know the most impregnable fortress in Italy.

All he knew was that the thing appeared to be formed of living, impregnable stone.

As the result of their deliberations they agreed that the place was impregnable.

At Althea the position had been so strengthened as to be now impregnable.