Definition from Wiktionary, the free dictionary
wake-up call (plural wake-up calls)
- A telephone call to awaken someone at a certain time, especially one requested by the person while staying at a hotel.
- She requested a five a.m. wake-up call from the front desk.
- (figuratively) An alert, reminder, or call to action caused by a dramatic event.
- The recent deaths should serve as a wake-up call to others at risk.
morning courtesy call