(a.) Not permeable; not permitting passage, as of a fluid. through its substance; impervious; impenetrable; as, India rubber is impermeable to water and to air.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). impermeable. Retrieved September 22, 2026, from http://smartdefine.org/impermeable/definitions/2019552 |
| Chicago | Webster's. 2011. "impermeable" http://smartdefine.org/impermeable/definitions/2019552 (accessed September 22, 2026). |
| Harvard | Webster's 2011, impermeable, Smart Define, viewed 22 September, 2026, <http://smartdefine.org/impermeable/definitions/2019552>. |
| MLA | Webster's. "impermeable" 27 May 2011. Web. 22 September 2026. <http://smartdefine.org/impermeable/definitions/2019552> |