Impervious

google

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mid 17th century: from Latin impervius (from in- ‘not’ + pervius ‘pervious’) + -ous.

wiktionary

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From Latin impervius(“that cannot be passed through”), from in-(“not”) + pervius(“letting things through”)

etymonline

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impervious (adj.)

1640s, from Latin impervius "not to be traverse, that cannot be passed through, impassible," from assimilated form of in- "not, opposite of" (see in- (1)) + pervius "letting things through, that can be passed through," from per "through" (from PIE root *per- (1) "forward," hence "through") + via "road" (see via (adv.)). Related: Imperviously; imperviousness.