irrefutable (adj.)youdaoicibaDictYouDict[irrefutable 词源字典]
1610s, from Latin irrefutabilis "irrefutable," from assimilated form of in- "not, opposite of" (see in- (1)) + refutabilis, from refutare (see refute). Related: Irrefutably; irrefutability.[irrefutable etymology, irrefutable origin, 英语词源]