Impenetrable and Impregnable

Impenetrable

Impenetrable adjective - Impossible to get through or into.
Usage example: the ancient temple was surrounded by vast stretches of impenetrable jungle

Impregnable is a synonym for impenetrable in property topic. In some cases you can use "Impregnable" instead an adjective "Impenetrable", when it comes to topics like invulnerable, impassible. popular alternative

Nearby Words: impenetrability, impenetrably

Impregnable

Impregnable adjective - Impossible to get through or into.
Usage example: the castle's supposedly impregnable walls

Impenetrable is a synonym for impregnable in invulnerable topic. You can use "Impenetrable" instead an adjective "Impregnable", if it concerns topics such as property, unyielding, impassible. popular alternative

Cite this Source
Impregnable and Impenetrable. (2016). Retrieved 2026, August 16, from https://thesaurus.plus/related/impenetrable/impregnable
Impenetrable & Impregnable. N.p., 2016. Web. 16 Aug. 2026. <https://thesaurus.plus/related/impenetrable/impregnable>.
Impregnable or Impenetrable. 2016. Accessed August 16, 2026. https://thesaurus.plus/related/impenetrable/impregnable.
Google Ngram Viewer shows how "impenetrable" and "impregnable" have occurred on timeline