Synonyms for impervious

Adjective

1. impervious (vs. pervious), imperviable, fast, acid-fast, colorfast, greaseproof, mothproof, moth-resistant, proof(predicate), resistant, runproof, ladder-proof, run-resistant, soundproof, impermeable

usage: not admitting of passage or capable of being affected; "a material impervious to water"; "someone impervious to argument"