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the-acid-test

/ðiː ˈæs.ɪd test/
IELTSAcademic
idiom

the acid test is a strict and important test that shows whether something is really good, true, or successful. It is often used for ideas, plans, products, or skills.

  • The launch will be the acid test for our new app.
  • This exam is the acid test of his English skills.
  • Real customer feedback is the acid test.

Adinary Nuance

The acid test is stronger than a simple test or check. It means the final, most revealing test that proves something in real life. Writers use it when they want to stress proof, not just evaluation. It is close to "touchstone" or "crucial test", but more direct and forceful.

In other languages

Vietnamese
phép thử quyết định
Spanish
prueba decisiva
Chinese
最终考验
Japanese
決定的な試金石
Korean
결정적 시험

Etymology

The phrase comes from chemistry and the old use of acid to test metals, especially gold, by seeing if they react. It became a figurative phrase in English in the 19th century.

Common phrases

the acid test of successthe acid test for a theorythe acid test of leadership

Synonyms

Related words

Frequently asked questions

Is the acid test formal or informal?
It is neutral to fairly formal. It appears often in writing, reports, and academic discussion.
What is the difference between the acid test and a simple test?
A simple test checks something. The acid test is the hardest or most revealing test.
Can I use the acid test in business writing?
Yes. It works well when you want to stress final proof or real-world results.
Is the acid test a common phrase?
Yes, it is well known in English, especially in formal and academic contexts.