impalpable (adj.)youdaoicibaDictYouDict[impalpable 词源字典]
c. 1500, from French impalpable, from Medieval Latin impalpabilis, from assimilated form of in- "not, opposite of" (see in- (1)) + palpabilis (see palpable). Figurative use from 1774. Related: Impalpably; impalpability.[impalpable etymology, impalpable origin, 英语词源]