litmus test

noun

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

Did you know?

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

For Trump, trade is not merely an economic issue, but a litmus test of whether America is winning or losing on the world stage. —Ryan Hass, Time, 30 May 2025

Philadelphia Eagles at Kansas City Chiefs, Week 2 In addition to a Super Bowl 59 rematch, this game will be an early season litmus test for the Chiefs’ offensive line. —Rohan Nadkarni, NBC news, 15 May 2025

Multiple states are gearing up for competitive gubernatorial elections next year, which will offer a litmus test for the parties on voter sentiment. —Caroline Vakil, The Hill, 6 May 2025

The denial Saturday by the Wisconsin court of appeals is the latest twist in Musk’s deep involvement in the race, which has set a record for spending in a judicial election and has become a litmus test for the opening months of Donald Trump’s presidency. —Thomas Beaumont, Twin Cities, 31 Mar. 2025

Word History

First Known Use

1913, in the meaning defined above

Rhymes for litmus test

• acquiesced
• coalesced
• dispossessed
• manifest
• overdressed
• overstressed
• prepossessed
• reassessed
• reinvest
• repossessed
• unaddressed
• uncompressed