Impenetrable is a synonym for impervious.
waterproof
responsive
Opaque
The rocks formed an impervious surface, and the rainwater flowed off into the town. In comic books, Superman is impervious to knives, bullets, and even bombs. The lawyer's logic was impervious to his opponent's arguments.
im
hard of hearing, stone deaf, oblivious, indifferent, ummoved, unsymphathetic, impervious, unhearing
The lead wall was impervious to radiation. He is impervious to her bad temper.
i am impervious to your insults
Wearing her kevlar jacket, Ash was impervious to any bullets fired at her.
The rain poured down, but the impervious roof kept us dry.
I am impervious from bullets and I destroyed the robbers.
Due to his trauma, the man was impervious to pain. The concrete floor was impervious to rain. The center for NORAD is buried under Cheyenne Mountain, and designed to be nearly impervious to nuclear attack.
A garden fish-pond needs an impervious lining.
Not pervious; not admitting of entrance or passage through; as, a substance impervious to water or air.
The book is so well researched it's impervious to criticism.
waterproof
responsive