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