Слово "impregnable". Англо-русский словарь Мюллера

Thus necessity, like a gravitating power, would soon form our newly arrived emigrants into society, the reciprocal blessings of which, would supersede, and render the obligations of law and government unnecessary while they remained perfectly just to each other; but as nothing but heaven is impregnable to vice, it will unavoidably happen, that in proportion as they surmount the first difficulties of emigration, which bound them together in a common cause, they will begin to relax in their duty and attachment to each other; and this remissness, will point out the necessity, of establishing some form of government to supply the defect of moral virtue.

That night (our third in Maple White Land) we had an experience which left a fearful impression upon our minds, and made us thankful that Lord John had worked so hard in making our retreat impregnable.

They were all impregnable, as the Party intended that they should be.

Sublime is the dominion of the mind over the body, that, for a time, can make flesh and nerve impregnable, and string the sinews like steel, so that the weak become so mighty. The boundaries of the farm, the grove, the wood-lot, passed by her dizzily, as she walked on; and still she went, leaving one familiar object after another, slacking not, pausing not, till reddening daylight found her many a long mile from all traces of any familiar objects upon the open highway.

While the society of up-country Georgia was not so impregnable as that of the Coast aristocrats, no family wanted a daughter to wed a man about whose grandfather nothing was known.

"Ashamed of drinking!" The tippler brought his speech to an end, and shut himself up in an impregnable silence.