1. a distress call or emergency signal

1. an international radio distress signal used by ships and aircraft in emergency situations
Usage: aviation; maritime

Examples

• The pilot radioed ‘Mayday, mayday!’ when the engine failed.
• Air traffic control received a mayday call from the small aircraft.
• The ship’s captain sent out a mayday signal before abandoning the vessel.
• Emergency responders quickly responded to the mayday transmission.
• The Coast Guard heard the mayday and dispatched a rescue helicopter.
• Flight 247 declared a mayday due to severe turbulence and engine trouble.