meltdown
noun [ C or U ] uk/ˈmelt.daʊn/ us/ˈmelt.daʊn/
(NUCLEAR)
（核电站核燃料的）熔毁
an extremely dangerous situation in a nuclear power station in which the nuclear fuel becomes very hot and melts through its container and escapes into the environment
(FAILURE)
（尤指金融方面的）灾难
a complete failure, especially in financial matters
financial/economic/market meltdown 金融／经济／市场崩溃
The last few months have seen the progressive meltdown of the country's political system. 过去几个月里，该国的政治体系一步步走向瓦解。
informal崩溃（指一个人极度悲伤而不能应对生活）
an occasion when a person becomes extremely upset and is not able to deal with a problem or situation