- Impossible to eliminate or destroy; impregnable.
1840, Thomas Carlyle, Heroes and Hero Worship:
- My one hope of the world, my inexpugnable consolation in looking at the miseries of the world, is that this is altering.
1911, H. G. Wells, The Country of the Blind, And Other Stories:
- It crept into one's mind, a distress as vague and inexpugnable as a sea fog on a spring morning, and presently one shivered and wanted to go indoors...
1915, Joseph Conrad, Victory:
- This seemed to be an inexpugnable refuge, where we could live untroubled and learn to know each other."