真的熔掉：核子事故
這是字面上的熔毀，也是其他用法借畫面的來源。所有比喻式的 meltdown，借的都是這裡的恐怖感：擋住危險的東西自己被燒穿了。
noun · B2
A very serious accident in which the fuel inside a nuclear reactor gets so hot that it melts and burns through its container, so that radiation can escape.
爐心熔毀
核心畫面
You can think of meltdown as the moment something gets too hot to keep its own shape. Heat builds up, nothing carries it away, and the thing that was holding everything in place and sinks. The two halves say it : melt, and down. Every use of the word points at that same moment — the point where what was containing the trouble stops being able to contain it.
meltdown 可以想成「熱到撐不住自己形狀」的那一刻。熱一直進來，卻沒有被帶走；原本把東西固定住的結構開始變軟，…更多收起
meltdown 可以想成「熱到撐不住自己形狀」的那一刻。熱一直進來，卻沒有被帶走；原本把東西固定住的結構開始變軟，然後往下塌。字面上兩塊就寫得很清楚：melt（熔化）＋ down（往下）。這個字的每一種用法都指著同一個時刻——本來用來把麻煩擋住的東西，自己撐不住了。所以熔的是燃料，就叫爐心熔毀；熔的是市場，就叫崩盤；熔的是一整套流程，就是癱瘓；熔的是一個人的耐力，就是情緒崩潰。它一定是快的、失控的、而且回不去原狀。From the word’s history
Wiktionary gives meltdown as melt (verb) + down (adverb), a deverbal from the verb melt down. The noun therefore keeps exactly the action of the verb: heating until shape is lost and the mass sinks.
Wiktionary 記載 meltdown 由 melt（動詞）加 down（副詞）構成，是從動詞片語 melt down 直接變來的名詞。所以這個名詞完整保留了那個動作：熱到失去形狀、整團往下塌。也因為它出身於一個動作，它描述的永遠是一個過程的結果，不是一種長期狀態。
Wiktionary entry for meltdown (etymology: melt + down, deverbal from melt down), supplied in this evidence packet
Three branches
系統熔掉：市場與運作垮台
把熔毀的畫面從金屬搬到「一套撐著大家的安排」上。看起來穩固的結構在很短時間內失去形狀，而且停不下來。
noun · C1
A sudden, very large fall in prices, or a fast collapse in the strength of a market, an industry or a whole economy.
崩盤；崩跌
人熔掉：情緒撐不住
同樣的熱，同樣的撐不住，只是這次撐著的是一個人的耐力。壓力累積久了，導火線往往是一件小事。
noun · B2
A sudden loss of control over your feelings, when someone shouts, cries, or simply cannot carry on with what they were doing.
情緒崩潰；爆掉