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

Nothing was found, and the call was dismissed as a false alarm.

From BBC ● Jul. 10, 2026

Doubts about the current bull market have started to creep in following Friday’s tech stock wipeout, but this wouldn’t be the first false alarm.

From The Wall Street Journal ● Jun. 8, 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

The ShakeAlert system that warns about imminent shaking arriving from earthquakes sent a false alarm across California on Thursday morning for a magnitude 5.9 temblor that did not happen.

From Los Angeles Times ● Dec. 22, 2025

Unsurprisingly, Mr. Weasley found, upon arrival at Mr. Moody’s heavily guarded house, that Mr. Moody had once again raised a false alarm.

From "Harry Potter And The Goblet Of Fire" by J. K. Rowling