safety valve

American  

noun

1. a device that, when actuated by a gas or vapor pressure above a predetermined level, opens and allows the gas or vapor to escape until its pressure is reduced to a pressure equal to or below that of the predetermined level.

2. a harmless outlet for emotion, tension, etc.

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safety valve British  

noun

1. a valve in a pressure vessel that allows fluid to escape when a predetermined level of pressure has been reached

2. a harmless outlet for emotion, energy, tension, etc

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Etymology

Origin of safety valve

First recorded in 1805–15

Example Sentences

See Examples For:

safety valve

Irritating but never truly dangerous, his antagonism is a safety valve for the class system and a flattering diversion for its proprietors.

From The Wall Street Journal ● Aug. 14, 2026

In addition, they note that now, parents will still have access to the debt, but thanks to the changes to repayment, they won’t have much of a safety valve if it becomes unmanageable.

From MarketWatch ● Jul. 1, 2026

Dot plots and macro projections serve as a pressure safety valve where disagreement can be hashed out, without harming the consistency of the policy message.

From Barron's ● Dec. 12, 2025

In that incident, the board’s investigation found multiple safety failures, including a severely eroded safety valve that allowed flammable gases to dangerously seep into unwanted areas.

From Los Angeles Times ● Oct. 4, 2025

There is one valve closed by a weight, although it is not in this case a safety valve; however, Papin describes the operation of such a valve.

From "The Invention of Science" by David Wootton