- (n.) Quality of being impenetrable.
- (n.) That property in virtue of which two portions of matter can not at the same time occupy the same portion of space.
- (n.) Insusceptibility of intellectual or emotional impression; obtuseness; stupidity; coldness.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). impenetrability. Retrieved September 21, 2026, from http://smartdefine.org/impenetrability/definitions/2019480 |
| Chicago | Webster's. 2011. "impenetrability" http://smartdefine.org/impenetrability/definitions/2019480 (accessed September 21, 2026). |
| Harvard | Webster's 2011, impenetrability, Smart Define, viewed 21 September, 2026, <http://smartdefine.org/impenetrability/definitions/2019480>. |
| MLA | Webster's. "impenetrability" 27 May 2011. Web. 21 September 2026. <http://smartdefine.org/impenetrability/definitions/2019480> |