wake-up call

Từ điển Oxford Advanced Learner 8th

ˈwake-up call 7 [wake-up call] BrE NAmE noun
1. a telephone call that you arrange to be made to you at a particular time, for example in a hotel, in order to wake you up
•I asked for a wake-up call at 6.30 a.m.
2. an event that makes people realize that there is a problem that they need to do sth about
•These riots should be a wake-up call for the government.