litmus test

American  

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.

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litmus test British  

noun

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

2. a critical indication of future success or failure

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Etymology

Origin of litmus test

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

Example Sentences

Still, many wondered if the Lakers’ litmus test would come from facing the defending champion Oklahoma City Thunder on Monday night.

From Los Angeles Times

The outcome of the first case will serve as a litmus test of jury reaction to evidence presented by the plaintiffs about whether the companies should be held liable.

From The Wall Street Journal

“I think ‘Wuthering Heights’ will be our litmus test to see if method dressing will spill over into historically inspired garments,” says Bretaña.

From Los Angeles Times

Pakistan received three bids on Tuesday for the privatisation of its embattled national carrier PIA, in what is seen as a litmus test of Islamabad's efforts to sell loss-making state firms.

From Barron's

Still, the ubiquity, complexity and accountability tax filing requires make it a good litmus test of the AI zealots and doomsayers’ beliefs.

From The Wall Street Journal