the edge of a cliff (= a high area of rock with a very steep side, often on a coast), where the ground falls very steeply down

Suddenly the back of the car was hanging over the cliff edge. 突然，汽车的后部挂在了悬崖边上。

a point where a situation changes very suddenly and completely in a damaging way, or where something suddenly becomes much worse

Retirement doesn't have to be a cliff edge, where you go from full-time work to no work at all overnight. 退休是一夜之间从全职工作到完全没有工作，但是这并不一定意味着生活处于悬崖边缘。

The quality of service has gone over a cliff edge recently. 服务质量最近突然像跌落悬崖一样变得很糟。