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