Impregnable
Impregnable adjective - Incapable of being defeated, overcome, or subdued.
Usage example: an impregnable fortress that had foiled one invader after another over the centuries
Safe is a synonym for impregnable in invulnerable topic. In some cases you can use "Safe" instead an adjective "Impregnable".
Safe
Mutual synonyms
Both words in one sentence
- It is a fact that no safe can ever be impregnable.
Source: Self-Destructing Security -
Described rather frighteningly by the Hunter and the narration, and essentially impregnable by normal means, it is rendered completely innocuous by Ringo, who, from a safe distance, telekinetically removes each Brother and drops him safely in a giant ice box made by John.
Source: Temple of Doom -
Naturally, other people would sometimes want the fabulous loot hidden away in someone's seemingly impregnable safe.
Source: Safecracking
Cite this Source
Safe and Impregnable. (2016). Retrieved 2026, July 21, from https://thesaurus.plus/related/impregnable/safe
Impregnable & Safe. N.p., 2016. Web. 21 Jul. 2026. <https://thesaurus.plus/related/impregnable/safe>.
Safe or Impregnable. 2016. Accessed July 21, 2026. https://thesaurus.plus/related/impregnable/safe.
Google Ngram Viewer shows how "impregnable" and "safe" have occurred on timeline