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

See Examples For:

false alarm

Still, that false alarm cost them about $160.

From The Wall Street Journal ● Sep. 5, 2026

A false alarm became part of the narrative when the Heat posted a link July 21 to a scheduled live stream titled “LeBron James Introductory Press Conference” to its YouTube channel.

From Los Angeles Times ● Jul. 24, 2026

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

From Science Daily ● Feb. 27, 2026

Historical records reveal there were several close calls in the early ’80s, including the 1983 Soviet nuclear false alarm that could have triggered a nuclear war.

From Slate ● Feb. 2, 2026

Because yeah, it was a false alarm, but I know it felt real to Dylan.

From "What If It's Us" by Becky Albertalli and Adam Silvera