From Longman Dictionary of Contemporary Englishfalse alarmˌfalse aˈlarm noun [countable]MISTAKEa situation in which people wrongly think that something bad is going to happenFire fighters responded to a false alarm at one of the college dormitories.The patient was okay – it was a false alarm.Examples from the Corpusfalse alarm• Your apprehension is based on the fear that the change might be a false alarm.• But the patient was okay, it was a false alarm, pleasethank them and send them on their way.• Those genes would produce a harmlessprotein that, once inside the body, would sound the false alarm of infection.