Impregnable
Impregnable adjective - Incapable of being defeated, overcome, or subdued.
Terrifying and impregnable are semantically related. In some cases you can use "Terrifying" instead an adjective "Impregnable".
Terrifying
Terrifying adjective - Causing fear.
Impregnable and terrifying are semantically related. Sometimes you can use "Impregnable" instead an adjective "Terrifying".
Mutual synonyms
Cite this Source
Terrifying and Impregnable. (2016). Retrieved 2026, July 22, from https://thesaurus.plus/related/impregnable/terrifying
Impregnable & Terrifying. N.p., 2016. Web. 22 Jul. 2026. <https://thesaurus.plus/related/impregnable/terrifying>.
Terrifying or Impregnable. 2016. Accessed July 22, 2026. https://thesaurus.plus/related/impregnable/terrifying.
Google Ngram Viewer shows how "impregnable" and "terrifying" have occurred on timeline