名詞 melt down:

1. severe overheating of the core of a nuclear reactor resulting in the core melting and radiation escaping
   同義詞：meltdown, nuclear meltdown
2. a disaster comparable to a nuclear meltdown
   同義詞：meltdown

動詞 melt down:

1. reduce or cause to be reduced from a solid to a liquid state, usually by heating
   同義詞：melt, run