- redouble (v.)
[redouble 词源字典]
- mid-15c., "double again, multiply" (trans.), from Middle French redoubler, from Old French re- "again" (see re-) + doubler "to double" (see double (v.)). Meaning "become twice as much" (intrans.) is from late 15c. Related: Redoubled; redoubling.[redouble etymology, redouble origin, 英语词源]