wake-up call

1. N-COUNT A wake-up call is a telephone call that you can arrange through an operator or at a hotel to make sure that you wake up at a particular time. (总机、宾馆等提供的) 叫醒电话

I book a wake-up call for 4:45 a.m. 我预订了凌晨4点45分的叫醒电话。

2. N-COUNT If you describe something bad that happens as a wake-up call, you mean that it acts as a warning that action needs to be taken to prevent something even worse from happening. 警钟

He urged her to treat the arrest as a wake-up call. 他力劝她把这次拘捕当作一次警钟。