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

Kavanaugh's appointment became a yardstick of the country's political divide last year, and a litmus test for Senate Democrats who are now running for president. Phillip M. Bailey, The Courier-Journal, "McGrath flip-flops on whether she would have voted to put Kavanaugh on the Supreme Court," 9 July 2019 The responses provided a litmus test for the broad political vitriol that now greets almost any news about Facebook. NBC News, "U.S. politicians hammer Facebook over Libra digital currency project," 18 June 2019 This year’s event, scheduled for Wednesday night, now looms as a litmus test, for both the museum and the city. Adrian Walker,, "What will the MFA’s woes mean for Juneteenth?," 16 June 2019 Beto ultimately did well at the ballot box with black voters, a key litmus test for 2020 candidates. Lucy Diavolo, Teen Vogue, "Beto O'Rourke Officially Announced His 2020 Presidential Campaign," 14 Mar. 2019 But given the events of the past two weeks, the effect of not having litmus tests is suddenly very clear. Lily Herman,, "Actually, Abortion Litmus Tests Are A Good Thing," 8 June 2019 What happens next will be a litmus test for Canada’s process of national reconciliation. Annabelle Timsit, Quartz, "Canada begins reconciliation process after inquiry into missing or murdered indigenous women ends," 7 June 2019 One reason Trump has become a conservative litmus test is that there’s a policy vacuum on the right, and Trump’s personality is filling the void. Jonah Goldberg, National Review, "USS John S. McCain Episode Speaks Volumes about Trumpism," 5 June 2019 This will season will be a litmus test for the defending champions, who will be out to prove their success is sustainable without Ty Jerome, Kyle Guy and De’Andre Hunter. Jeremy Woo,, "Top 25 Reset: How Draft Decisions Changed Our 2019-20 Preseason Rankings," 5 June 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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Statistics for litmus test

Last Updated

17 Jul 2019

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Time Traveler for litmus test

The first known use of litmus test was in 1913

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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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More from Merriam-Webster on litmus test

Thesaurus: All synonyms and antonyms for litmus test

Spanish Central: Translation of litmus test

Nglish: Translation of litmus test for Spanish Speakers

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