megadeath (n.)youdaoicibaDictYouDict[megadeath 词源字典]
1953, from mega- in scientific sense (one million) + death (n.). The death of one million persons, as a measure of the effectiveness of nuclear weapons. The resulting pile of dead bodies would be a megacorpse, according to writings on the topic.[megadeath etymology, megadeath origin, 英语词源]