burning (adj.)youdaoicibaDictYouDict[burning 词源字典]
Old English in the literal sense; c. 1300 figurative, present participle adjective from burn (v.)). Burning question matches French question brûlante, German brennende Frage. Burning bush is from Exodus III. Burning glass is attested from 1560s.[burning etymology, burning origin, 英语词源]