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

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

Chronic pain, however, continues even after the injury has healed, creating a kind of false alarm that can last for weeks, months, or years.

From Science Daily • Apr. 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

Others, the sweet relief of a false alarm and disaster narrowly averted.

From Los Angeles Times • Dec. 9, 2025

These orders were written up and posted on the tents, and the Boss let it be known that he might at any time give a false alarm as a drill.

From "Shipwreck at the Bottom of the World" by Jennifer Armstrong