|Origin:||impervius, from pervius 'allowing things to pass through', from per 'through' + via 'way'|
Related topics: Geology
im‧per‧vi‧ous [not before noun]
not affected or influenced by something and seeming not to notice it
His ego was impervious to self-doubt.
not allowing anything to enter or pass through:
impervious volcanic rock
materials that are impervious to water