derail
Americanverb (used with object)
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to cause (a train, streetcar, etc.) to run off the rails of a track.
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to cause to fail or become deflected from a purpose; reduce or delay the chances for success or development of.
Being drafted into the army derailed his career for two years.
verb (used without object)
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(of a train, streetcar, etc.) to run off the rails of a track.
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to become derailed; go astray.
noun
verb
noun
Other Word Forms
Derived Forms
Inflected Forms
Participles
Conjugated Forms
Present
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derailsimple
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derailssimple
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have derailedperfect
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has derailedperfect
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am derailingprogressive
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are derailingprogressive
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is derailingprogressive
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have been derailingperfect progressive
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has been derailingperfect progressive
Past
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derailedsimple
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had derailedperfect
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was derailingprogressive
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were derailingprogressive
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had been derailingperfect progressive
Future
Etymology
Origin of derail
First recorded in 1840–50; from French dérailler, equivalent to dé- negative prefix + -railler, verbal derivative of rail “bar, beam” (from English ); see origin at de- rail 1
Explanation
When a train or a subway derails, its wheels accidentally leave the tracks. Train cars that derail can cause the cars behind them to crash. Mistakes by engineers or flaws in the track can derail a train or trolley, sending it off the rails and sometimes injuring the passengers. You can also use the verb derail figuratively, to mean "hinder someone" or "divert a process from going in its intended direction." For example, terrorists might derail ongoing peace talks by blowing up a bus. The word comes from the French dérailler, "go off the rails."
Vocabulary lists containing derail
This Week in Words: October 1 - 6, 2017
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This Week in Words: December 16 - 22, 2017
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
“I also think you have outliers of the party that sometimes suck all the oxygen out of the room and maybe derail that message.”
From Los Angeles Times ● Jul. 17, 2026
It isn’t clear whether a surging supply of shares can derail a market that has a lot going for it.
From The Wall Street Journal ● Jul. 15, 2026
Don’t let your loyalty derail your financial future.
From MarketWatch ● Jul. 15, 2026
There was a brief point when, by targeting leg side, Devine threatened to derail England but Bell - a much-improved death bowler - returned to have her lbw in the 16th over.
From BBC ● Jun. 27, 2026
A universe where he does derail it and she is not able to fix it.
From "The Sun Is Also a Star" by Nicola Yoon
“I don’t see anything that derails economic or earnings growth,” said Amanda Agati, chief investment officer at PNC’s asset management group.
From Barron's ● Jul. 1, 2026
“Most people think of retirement risk in terms of market crashes,” said Jeff Judge, a certified financial planner in Forest Hill, Md. “Healthcare is the one that actually derails the most plans I’ve seen.”
From MarketWatch ● Jun. 15, 2026
Their closeness derails Rausch’s “three steps ahead” scheming.
From Salon ● Jan. 28, 2026
He’s worried about a crisis—like what happened with the nuclear industry—that sparks drastic policy changes that derails development.
From The Wall Street Journal ● Oct. 18, 2025
I need to get her out of here before my family derails my life just as it’s getting started.
From "The Sun Is Also a Star" by Nicola Yoon
NHK aired footage from elsewhere in the southwestern Kumamoto region on Kyushu island showing several blazes, damaged bridges, a derailed cargo train and a number of houses threatening to topple over.
From Barron's ● Jul. 28, 2026
The retailer had previously sought to go public in New York and considered a listing in London, but those efforts were derailed by escalating trade tensions between Washington and Beijing.
From The Wall Street Journal ● Jul. 27, 2026
If an agreement as superficial as the memorandum of understanding — which deferred thornier issues for late negotiations — was derailed, then there’s little option other than repeated cycles of violence.
From Los Angeles Times ● Jul. 20, 2026
Concerns around fuel costs — the second-highest cost for airlines after labor — had derailed Delta Air Lines’
From MarketWatch ● Jul. 15, 2026
These stories spread the false claim that Slave Power agents had derailed the President’s train and killed his son, Bennie.
From "American Spirits" by Barb Rosenstock
A military campaign in Lebanon risks derailing those gains.
From The Wall Street Journal ● Jul. 21, 2026
“True financial independence means you reasonably control what allows you to live the life you want without external things derailing you,” Welborn said.
From MarketWatch ● Jul. 12, 2026
The Gunners boss was then asked how he can prevent this form rolling into the rest of the season and derailing their Champions League and Premier League campaigns.
From BBC ● Apr. 4, 2026
For now, he is focused on derailing the Nexstar-Tegna deal.
From Los Angeles Times ● Mar. 20, 2026
This was the only way to keep Cynthia from disrupting and derailing the entire lesson.
From "Look Both Ways" by Jason Reynolds
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
