third rail

noun

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.
Medicare trustees have sounded the alarm on the Hospital Trust Fund for years, though the warnings have mostly been ignored by Congress, as lawmakers view Medicare reforms as a political third rail. Aris Folley, The Hill, 18 June 2025 The two Tennessee administrators had just stepped on the third rail of college sports. Seth Emerson, New York Times, 29 May 2025 President Rob Free said, after damage to the third rail was discovered following Amtrak work. Evan Simko-Bednarski, New York Daily News, 7 May 2025 Changes to Medicaid have proven contentious, and Medicare is often considered a political third rail. Joseph Choi, The Hill, 5 June 2025 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

Browse Nearby Words

Cite this Entry

“Third rail.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/third%20rail. Accessed 10 Jul. 2025.

More from Merriam-Webster on third rail

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!