point of no return

point-of-no-return的词性：
n.（名词）

1. The point in a course of action beyond which reversal is not possible.
欲罢不能的状态：在行动过程中超越返回将不再可能的那一点

2. The point in the flight of an aircraft beyond which there is insufficient fuel for return to the starting point.
不可返回点；无还点：一架飞机飞行中，飞机没有足够的油料返回出发点的那一点