Impenetrable
Impenetrable adjective - Impossible to get through or into.
Viscous and impenetrable are semantically related. In some cases you can use "Viscous" instead an adjective "Impenetrable".
Nearby Words: impenetrability, impenetrably
Viscous
Viscous adjective - Being of a consistency that resists flow.
Impenetrable and viscous are semantically related. Sometimes you can use "Impenetrable" instead an adjective "Viscous".
Related pairs
Cite this Source
Viscous and Impenetrable. (2016). Retrieved 2026, August 03, from https://thesaurus.plus/related/impenetrable/viscous
Impenetrable & Viscous. N.p., 2016. Web. 03 Aug. 2026. <https://thesaurus.plus/related/impenetrable/viscous>.
Viscous or Impenetrable. 2016. Accessed August 03, 2026. https://thesaurus.plus/related/impenetrable/viscous.
Google Ngram Viewer shows how "impenetrable" and "viscous" have occurred on timeline