Impregnable
Impregnable adjective - Incapable of being defeated, overcome, or subdued.
Riskless and impregnable are semantically related In some cases you can use "Riskless" instead an adjective "Impregnable".
Riskless
Riskless adjective - Thought to be devoid of risk.
Impregnable and riskless are semantically related in safe topic. You can use "Impregnable" instead an adjective "Riskless".
Mutual synonyms
Related pairs
Cite this Source
Riskless and Impregnable. (2016). Retrieved 2026, August 15, from https://thesaurus.plus/related/impregnable/riskless
Impregnable & Riskless. N.p., 2016. Web. 15 Aug. 2026. <https://thesaurus.plus/related/impregnable/riskless>.
Riskless or Impregnable. 2016. Accessed August 15, 2026. https://thesaurus.plus/related/impregnable/riskless.
Google Ngram Viewer shows how "impregnable" and "riskless" have occurred on timeline