third rail

noun

Synonyms of third railnext
1
: a metal rail through which electric current is led to the motors of an electric vehicle (such as a subway car)
2
: a controversial issue usually avoided by politicians

Examples of third rail in a Sentence

Social Security is the third rail of American politics.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The idea of restricting defenses against nuclear attack has long been a third rail in American politics, especially among Republicans. Jeffrey Lewis, Foreign Affairs, 1 Sep. 2026 Flagrantly practicing an especially ribald strain of cringe comedy that brushes several third rails, often simultaneously, the show could have been a disastrous gambit. Paula Mejía, New Yorker, 17 Aug. 2026 The guild pulling its sponsorship of Urbanworld reflects how AI remains a third rail within the creative community, even as everyone from directors to actors to director-actor-executive hybrids embrace it in different ways. Corbin Bolies, Variety, 30 July 2026 That is part of why K-12 schools have long been treated like a third rail. Karl Mawhinney, Forbes.com, 22 July 2026 See All Example Sentences for third rail

Word History

First Known Use

1867, in the meaning defined at sense 1

Time Traveler
The first known use of third rail was in 1867

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Cite this Entry

“Third rail.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/third%20rail. Accessed 14 Sep. 2026.

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