1. A phone call that one schedules to be placed to one's hotel room in order to be woken up at a certain time. I set an alarm and scheduled a wake-up call so there's no way I oversleep for the first conference session tomorrow.
2. An event that triggers a sense of urgency or the motiviation to make a change. Primarily heard in US, Australia. Harold's sudden chest pain was the wake-up call he needed to finally see his doctor.That terrible car accident was just the wake-up call I needed to quit my boring office job and start acting again.
A portentous event, report, or situation that brings an issue to immediate attention. For example, The rise in unemployment has given a wake-up call to state governments, or The success of the online subscription is a wake-up call to publishers. This metaphoric term originated in the second half of the 1900s for a telephone call arranged in advance to awaken a sleeper, especially in a hotel. Its figurative use dates from about 1990.