Impregnable
Impregnable adjective - Incapable of being defeated, overcome, or subdued.
Reasonable and impregnable are semantically related. In some cases you can use "Reasonable" instead an adjective "Impregnable".
Reasonable
Reasonable adjective - According to the rules of logic.
Impregnable and reasonable are semantically related. Sometimes you can use "Impregnable" instead an adjective "Reasonable".
Mutual synonyms
Cite this Source
Reasonable and Impregnable. (2016). Retrieved 2026, July 21, from https://thesaurus.plus/related/impregnable/reasonable
Impregnable & Reasonable. N.p., 2016. Web. 21 Jul. 2026. <https://thesaurus.plus/related/impregnable/reasonable>.
Reasonable or Impregnable. 2016. Accessed July 21, 2026. https://thesaurus.plus/related/impregnable/reasonable.
Google Ngram Viewer shows how "impregnable" and "reasonable" have occurred on timeline