third rail

noun

|Updated on: 15 Jun 2018

Examples: third rail in a Sentence

Definition of third rail

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

See third rail defined for English-language learners

Examples of third rail in a Sentence

Social Security is the third rail of American politics.

Recent Examples of third rail from the Web

Metro said the Red Line train that broke down at Forest Glen at the height of the afternoon rush Tuesday struck a metal object, resulting in smoke when the object came into contact with the electrified third rail.

— faiz siddiqui, Washington Post, "Red Line single-tracking between Silver Spring and Wheaton Metro stations after train breaks down sending smoke into tunnel," 5 June 2018
The misogynistic term remains the third rail of profanity.

— stephanie ebbert, BostonGlobe.com, "Why the c-word is still the third rail of profanity," 1 June 2018
Maybe outright comparing black people to apes without even disguising it is a third rail even for Trump people?

— jonathan chait, Daily Intelligencer, "DI Politics Chat: A Low Barr," 29 May 2018
The man, Jacinto Suarez, did not come in contact with the electrified third rail and was not struck by a train.

— matthew haag and ashley southall, New York Times, "Man, 65, Dies After Teenager Punches Him, Knocking Him Onto Subway Tracks," 3 Jan. 2018
These reforms were considered third rails in Mexican politics only a decade earlier.

— mary anastasia o’grady, WSJ, "Mexico’s Two-Man Race," 29 Apr. 2018
The fund's earnings have historically gone toward dividends, cash sums paid directly to residents each year, and the program has been seen as the third rail of Alaska politics for decades: Touch it and you risk being zapped at the ballot box.

— nathaniel herz, Anchorage Daily News, "A $5,000 PFD check? As boosters push for one, lawmakers call it ‘instant gratification’," 1 Mar. 2018
Brown, 57, is under pressure to address the problem but she's been careful around what some call the political third rail for Oregon Democrats.

— hillary borrud, OregonLive.com, "Kate Brown poised for easy win in Democratic primary, thanks to union support," 5 May 2018
October 24, 2017 at 12:26 AM Oy, the third rail of covering football.

— jeff potrykus, Milwaukee Journal Sentinel, "UW football chat with Jeff Potrykus," 23 Oct. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'third rail.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of third rail

1867

in the meaning defined at sense 1

See Words from the same year

NEW! Time Traveler

THIRD RAIL Defined for English Language Learners

third rail

noun

Definition of third rail for English Language Learners

: a metal rail on a train track that carries electric current to the train's motor
: a difficult issue that politicians try to avoid talking about

Learn More about third rail

See words that rhyme with third rail Britannica.com: Encyclopedia article about third rail

Seen and Heard

What made you want to look up third rail? Please tell us where you read or heard it (including the quote, if possible).

show

third rail

Definition of third rail

Examples of third rail in a Sentence

Recent Examples of third rail from the Web

First Known Use of third rail

THIRD RAIL Defined for English Language Learners

third rail

Definition of third rail for English Language Learners

Learn More about third rail

Seen and Heard

WORD OF THE DAY

quail

BROWSE DICTIONARY

Test Your Vocabulary

Words at Play

'Than': What Follows It and Why

Words We're Watching: 'B side'

Can You Use 'Comprised of'?

Words We're Watching: '-iversary'

Ask the Editors

Ghost Word

2017 Word of the Year: Behind the Scenes

Literally

Is Singular 'They' a Better Choice?

Word Games

Name More Food!

Yearbook Superlatives Quiz

Spell It

Word Winder's CrossWinder

Trending: 'Asylum' Trends as Policies Draw Attention

'Than': What Follows It and Why

Name More Food!

9 Words for Transnational Currencies

Ghost Word

third rail

Definition of third rail

Examples of third rail in a Sentence

Recent Examples of third rail from the Web

First Known Use of third rail

THIRD RAIL Defined for English Language Learners

third rail

Definition of third rail for English Language Learners

Learn More about third rail

Seen and Heard

Love words? Need even more definitions?

Love words? Need even more definitions?

Words at Play

Ask the Editors

Word Games

Trending: 'Asylum' Trends as Policies Draw Attention

'Than': What Follows It and Why

Name More Food!

9 Words for Transnational Currencies

Ghost Word