litmus test

noun

1. Chemistry.,  the use of litmus paper or solution to test the acidity or alkalinity of a solution.

2. a crucial and revealing test in which there is one decisive factor.

litmus test

noun

1. a test to establish the acidity or alkalinity of a mixture

2. a critical indication of future success or failure

Word History and Origins

Origin of litmus test¹

First recorded in 1955–60; so called from chemical tests in which litmus or litmus paper is an indicator

Example Sentences

There are no political, religious or secularist orthodoxies or litmus tests.

Read more on The Wall Street Journal

Some also see cryptocurrency as increasingly a litmus test for where stocks will go.

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The proposals would be a “litmus test for the fight against red tape in Brussels and Strasbourg,” German Chancellor Friedrich Merz told a joint summit on digital sovereignty with French President Emmanuel Macron.

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And the popular tech YouTuber Marques Brownlee said it was a "litmus test" for fans who "buy or defend anything Apple releases".

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The all-volunteer organization sends applicants a lengthy questionnaire with dozens of litmus test questions: Do they support diverting funds away from law enforcement?

Read more on Los Angeles Times