litmus test


Definition of litmus test

: a test in which a single factor (such as an attitude, event, or fact) is decisive

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Litmus Test Has Scientific Origins

It was in the 14th century that scientists discovered that litmus, a mixture of colored organic compounds obtained from lichen, turns red in acid solutions and blue in alkaline solutions and, thus, can be used as an acid-base indicator. Six centuries later, people began using litmus test figuratively. It can now refer to any single factor that establishes the true character of something or causes it to be assigned to one category or another. Often it refers to something (such as an opinion about a political or moral issue) that can be used to make a judgment about whether someone or something is acceptable or not.

Examples of litmus test in a Sentence

The party is using attitudes about gun control as a litmus test for political candidates.
Recent Examples on the Web Some think anti-Semitism is a litmus test; others genocide. Sarah Churchwell, The New York Review of Books, "American Fascism: It Has Happened Here," 22 June 2020 While the state’s most populous city and COVID-19 hot spot is making progress in controlling spread of the coronavirus, a litmus test awaits with the July Fourth holiday, the mayor said. USA TODAY, "Refusal to distance, pawn shop boom, hospital planning: News from around our 50 states," 4 July 2019 The hearings, which will likely wrap late this year, are regarded by many observers as a litmus test for whether Korea’s courts are truly independent of the powerful business interests that hold sway over the economy. Sohee Kim,, "Samsung Billionaire’s Fate at Risk Despite Role in Virus Fight," 14 June 2020 Maybe in some, small way, Collinsworth represented a litmus test of sorts for Riley, who already had tangled for years with his big-time teammate Isaac Curtis. Paul Daugherty,, "Paul Daugherty: Former teammates remember Cincinnati Bengals great Ken Riley," 7 June 2020 In two-decades of Chinese rule, the Tiananmen memorial was always something that set Hong Kong apart, a litmus test for whether the city's freedoms and autonomy were still protected. James Griffiths, CNN, "Hong Kong marks Tiananmen massacre for what many fear will be the last time," 3 June 2020 What the state decides to do with South African Airways could be a litmus test for that resolve. Antony Sguazzin,, "Gordhan Stakes His Reputation and South Africa’s on Airline," 26 May 2020 In 2020, paid sick leave has emerged as a low-key litmus test issue for Democratic presidential candidates. Gilbert Garcia,, "Garcia: Bloomberg’s support for paid sick leave called into question," 19 Feb. 2020 The next big litmus test for House Republicans will be the open seat in California's 25th district, after Democrat Rep. Katie Hill announced her resignation. Caitlin Conant, CBS News, "2020 Daily Trail Markers: Elizabeth Warren takes aim at Mike Bloomberg's billions," 25 Nov. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'litmus test.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of litmus test

1913, in the meaning defined above

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The first known use of litmus test was in 1913

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Last Updated

16 Jul 2020

Cite this Entry

“Litmus test.” Dictionary, Merriam-Webster, Accessed 8 Aug. 2020.

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More Definitions for litmus test

litmus test


English Language Learners Definition of litmus test

: something (such as an opinion about a political or moral issue) that is used to make a judgment about whether someone or something is acceptable

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