knock-on effect
noun [ C usually singular ] mainly UK uk/ˈnɒk.ɒn ɪˌfekt/ us/ˈnɑːk.ɑːn ɪˌfekt/
连锁反应
When an event or situation has a knock-on effect, it causes other events or situations, but not directly.
If one or two trains run late, it has a knock-on effect on the entire rail service. 如果有一两列火车晚点，会进而影响整个铁路系统。