1. Not admitting of passage or capable of being affected
   "a material impervious to water"; "someone impervious to argument"
   - imperviable

See also: acid-fast, colorfast [US], colourfast [Brit, Cdn], corrosion-resistant, fast, greaseproof, impermeable, imperviousness, ladder-proof, mothproof, moth-resistant, proof, resistant, rot-resistant, runproof, run-resistant, soundproof

Antonym: pervious

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• Special Weapons and Tactics team
• specialisation
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• specifiable