Acid test and litmus test are terms from chemistry that have migrated into mainstream English to become idioms. An idiom is a word, group of words or phrase that has a figurative meaning that is not easily deduced from its literal meaning. We will examine the meaning of the phrases acid test and litmus test, where these terms came from and some examples of their use in sentences.
An acid test is a severe challenge that measures the strength or endurance of someone or something, a challenge that will reveal the mettle or value of someone or something. The term acid test is derived from an actual test. Acid has been used for centuries to test whether a sample of gold is genuine or not. Other acid tests have been used to test whether food, fabric or other goods are pure. The term took on its figurative sense in the United States in the mid-1800s.
A litmus test is a challenge that will decisively reveal where someone or something stands, or whether someone or something is viable or effective in regard to stated goals. Litmus test is often used in politics to describe a question to the political candidate that, when answered, defines his values and morals to a majority of the electorate. The term litmus test also is derived from an actual chemical test that measures acidity or alkalinity discovered in the 1800s. The term took on its figurative sense in the United States in the 1950s.
The acid test of Trump’s maverick leadership has come – can he save himself? (The Guardian)
Top of the table Castleford Tigers face the acid test of their title credentials when the much anticipated first meeting with Wigan Warriors takes place at the DW Stadium tonight. (Pontefract and Castleford Express)
Speaking at Canary Wharf in London, Carney said Brexit and possibly two years of negotiations would be a “litmus test” for responsible financial globalization. (Deutsche Welle)
U.S. Sen. Richard Blumenthal pledged Friday to oppose the nomination of Neil Gorsuch to the Supreme Court through all available means, saying the Harvard-educated, conservative jurist failed during his confirmation hearings to demonstrate he is not bound by an anti-abortion litmus test imposed by President Trump. (The Connecticut Mirror)
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