impervious (adj.)youdaoicibaDictYouDict[impervious 词源字典]
1640s, from Latin impervius "that cannot be passed through," from assimilated form of in- "not, opposite of" (see in- (1)) + pervius "letting things through," from per "through" + via "road." Related: Imperviously; imperviousness.[impervious etymology, impervious origin, 英语词源]