holocaust
noun [ C ] uk/ˈhɒl.ə.kɔːst/ us/ˈhɑː.lə.kɑːst/
大屠杀，大毁灭，浩劫
a very large amount of destruction, especially by fire or heat, or the killing of very large numbers of people
A nuclear holocaust (= destruction caused by nuclear weapons) would leave few survivors. 核浩劫后几乎不会留下什么幸存者。