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