cave-in
/ˈkeɪvɪn/noun
1- a collapse of a roof or similar structure, typically underground（屋顶等）倒塌, 坍塌（尤指地陷）：
a mine cave-in.
矿井坍塌。
1.1
- in sing. figurative an instance of yielding or submitting under pressure〈喻〉屈服于压力：
the government's cave-in to industry pressure.
政府对实业界压力的屈服。