土石往內塌
核心畫面的字面版本：真的有土石掉下來。
noun · B2
A sudden fall of the roof, walls or ground of something such as a mine, a tunnel or a hole; also the earth and rock this leaves lying in the way.
坍塌／塌陷
核心畫面
Picture a mine roof that has been holding up of earth. The weight never stops pressing, and one day the roof stops holding and everything drops . A cave-in is that moment, packed up as a thing you can put a or the in front of.
可以想成礦坑的頂撐著上面幾噸重的土。壓力一直在，沒停過。有一天頂撐不住了，整片往裡面掉下來。cave-in 就是那一…更多收起
可以想成礦坑的頂撐著上面幾噸重的土。壓力一直在，沒停過。有一天頂撐不住了，整片往裡面掉下來。cave-in 就是那一下，被包成一個名詞，前面可以加 a 或 the。這個畫面有兩個部分：一個是往內垮的動作，一個是垮完留在那裡的一堆東西。兩個部分英文都用同一個字。再把這個畫面從土石換成人，就得到第二個意思。From the word’s history
Deverbal from the phrasal verb cave in — the action turned into a noun.
它是從動詞片語 cave in 直接變成名詞的，也就是把「往內塌」這個動作整包拿來當一件事講。
Wiktionary, entry 'cave-in' (packet etymology_text: 'Deverbal from cave in.')
Two branches
人撐不住了
把撐著的屋頂換成撐著立場的人：壓力一樣沒停過，最後一樣是整個往內垮。這是借畫面來講人，不是說這兩個意思有先後的歷史關係。
noun · C1
The moment when a person or a group stops fighting against something and lets the other side have what it wants.
讓步／屈服
原始詞典資料4 筆記錄
以下是外部詞典記錄的用法，原文照列，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
cave-innoun
- 1
The act of something collapsing or caving in.
- We were warned away from the rickety old mine because of the danger of cave-ins.
- 2
The location where something has caved in.
- We couldn't get past the cave-in blocking the tunnel.
- 3
The act of relenting.
- It was a cave-in, but I let my child have a candy to shut her up.
這個拼法也被記錄為下列字的變化形：
資料來源：英文維基詞典 English Wiktionary（CC BY-SA 4.0）。 原文照列，未經改寫。