WordWeb Online

1. A warning to take action concerning something that was overlooked or neglected
   "the bombing was a wake-up call to strengthen domestic security"
    
2. A telephone call that you request be made a specific time in order to wake you up at that time (especially in hotels)
   "she left a wake-up call for 7 a.m."

Derived forms: wake-up calls

Type of: call, phone call, telephone call, warning