名詞 cave-in:

1. the sudden collapse of something into a hollow beneath it
   同義詞：cave in, subsidence

動詞 cave-in:

1. break down, literally or metaphorically
   同義詞：collapse, fall in, cave in, give, give way, break, founder

cave-in

n.（名詞）

A collapse, as of a tunnel or structure.
坍陷：坍陷，如隧道或建筑的塌陷
A place where a cave-in has occurred.
坍陷處：出現(xiàn)塌陷的地方
An act or instance of ceasing opposition or resistance:
投降：終止反對或抵抗的行動或情況：
例句：
The vote was seen as a cave-in to the demands of the administration.
選舉被看作是對管理要求的投降