derail

American  

[dee-rayl] / diˈreɪl /

verb (used with object)

• derails,
  present (3rd person singular)
• derailed,
  past participle,  past
• derailing
  present participle

1. to cause (a train, streetcar, etc.) to run off the rails of a track.

2. 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)

• derails,
  present (3rd person singular)
• derailed,
  past participle,  past
• derailing
  present participle

1. (of a train, streetcar, etc.) to run off the rails of a track.

2. to become derailed; go astray.

noun

1. a track device for derailing rolling stock in an emergency.

derail British  

/ dɪˈreɪl /

verb

1. to go or cause to go off the rails, as a train, tram, etc

---

noun

1. Also called: derailer. a device designed to make rolling stock or locomotives leave the rails to avoid a collision or accident

Other Word Forms

Derived Forms

• derailment
  noun

Inflected Forms

Participles

• derailing
  present
• derailed
  past

Conjugated Forms

Present

• derail
  simple
• derails
  simple
• have derailed
  perfect
• has derailed
  perfect
• am derailing
  progressive
• are derailing
  progressive
• is derailing
  progressive
• have been derailing
  perfect progressive
• has been derailing
  perfect progressive

Past

• derailed
  simple
• had derailed
  perfect
• was derailing
  progressive
• were derailing
  progressive
• had been derailing
  perfect progressive

Future

• will derail
  simple
• will have derailed
  perfect
• will be derailing
  progressive
• will have been derailing
  perfect progressive

---

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."

Example Sentences

See Examples For:

derail derails derailed derailing

The Rams beat the Chargers by 13, so miscues by the special teams didn’t derail them.

From Los Angeles Times ● Nov. 2, 2026

“If anybody tries to derail that process, they’re doing great harm to Venezuela,” U.S.

From The Wall Street Journal ● Oct. 29, 2026

Anthropic’s success depends on its ability to develop and release increasingly powerful AI models, and the company faces unique risks that could derail its business.

From Los Angeles Times ● Oct. 27, 2026

Now, Wall Street is taking a more cautious approach, looking more closely at the debt underpinning the AI boom and whether that stands to derail big growth projections that stretch years into the future.

From MarketWatch ● Oct. 23, 2026

“Indeed we did. However, not even that bit of bad luck can derail our juggernaut!”

From "Escape from Mr. Lemoncello's Library" by Chris Grabenstein

“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

Dodgers pitcher Tyler Glasnow laments not having an opportunity to play in the postseason after another elbow injury derails his season.

From Los Angeles Times ● Sep. 21, 2024

My sudden shaking derails my mom’s questioning and sends her into doctor mode.

From "Everything, Everything" by Nicola Yoon

A lack of hotel space, however, nearly derailed “North of North” entirely.

From Los Angeles Times ● Nov. 6, 2026

His return to his hometown club, however, has been derailed by a contract dispute which he has described as "incomprehensible".

From BBC ● Oct. 19, 2026

A number of civil lawsuits have been filed against shoe manufacturers by track stars, including an Olympian, who allege, among other things, that wearing high-stack shoes with carbon plates caused injuries that derailed their careers.

From The Wall Street Journal ● Oct. 10, 2026

The Drumcree parade dispute began in the mid-1990s and almost derailed the peace process at the time.

From BBC ● Oct. 1, 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

But that’s not a new development: The chart above shows that has happened multiple times before, without derailing the longer-term uptrend.

From MarketWatch ● Oct. 16, 2026

She flags that a September Fed rate increase could still result in a “knee-jerk correction” without derailing the broader recovery.

From The Wall Street Journal ● Sep. 14, 2026

At one point early on, high levels of soil contaminants become a concern at fields across the region, almost derailing the whole season.

From Los Angeles Times ● May 13, 2026

Midway through this season, though, it looked like things were derailing for Palace.

From BBC ● Apr. 16, 2026

This was the only way to keep Cynthia from disrupting and derailing the entire lesson.

From "Look Both Ways" by Jason Reynolds

Random Word

Spin the wheel and learn a new word!

---

Related Words

• block
• deter
• filibuster
• hamper
• hinder
• impede
• interfere
• stall
• stonewall
• thwart

---