false alarm

American  

noun

1. a false report of a fire in progress to a fire department.

2. something that excites unfounded alarm or expectation.

   Rumors of an impending transit strike proved to be a false alarm.

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false alarm British  

noun

1. a needless alarm given in error or with intent to deceive

2. an occasion on which danger is perceived but fails to materialize

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false alarm Idioms  

1. A warning signal that is groundless, made either by mistake or as a deliberate deception. For example, The rumor that we were all going to get fired was just a false alarm, or Setting off a false alarm is a criminal offense. This expression, first recorded in 1579, today is often used for a report of a nonexistent fire.

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Etymology

Origin of false alarm

First recorded in 1570–80

Example Sentences

This misinterpretation activates the cell's innate immune system, creating a false alarm that can lead to inflammation and disease.

From Science Daily

The resiliency report also found that residents experienced “evacuation warning fatigue” from routine false alarms, making them hesitant to evacuate.

From Los Angeles Times

Reul said they saw "no smoke, no smell of fire, or damage", so they "concluded it was a false alarm", which he said was not unusual.

From BBC

Both false alarms and true warnings will be improved by knowing the difference between a bad day on the mountain and a positive signal that a volcano is on the brink of eruption.

From Literature

On occasion, clips of them confronting federal agents have spread on social media, but many of the tips they chase are false alarms.

From Barron's