an unwise action that is likely to have an unpleasant or dangerous effect

We can't afford to make any false moves once we're in enemy territory. 一旦进入敌方区域，我们绝不能轻举妄动。

"One false move and you're dead! (= I will kill you)" shouted the gunman. “敢乱动一下，就要你的命！” 持枪歹徒吼道。