선박이나 항공기가 위급한 상황에서 무선으로 보내는 국제적인 조난 신호.
An international radio distress signal used by ships and aircraft to communicate a life-threatening emergency.
예문:
"The captain sent out a mayday when the ship began taking on water."
"Air traffic control responded immediately to the pilot's mayday call."
"A mayday signal is only used in situations of grave and imminent danger."