derail

verb

de·​rail di-ˈrāl How to pronounce derail (audio)
dē-
derailed; derailing; derails
Synonyms of derailnext

transitive verb

1
: to cause to run off the rails
2
a
: to obstruct the progress of : frustrate
Security problems derailed the tour.
b
: to upset the stability or composure of
… divorce … can seriously derail an employee.Joanne Gordon

intransitive verb

: to leave the rails
derailment noun

Examples of derail in a Sentence

The train derailed in heavy snow. The train was derailed by heavy snow.
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 tech industry fears that regulations specifically targeting AI could derail momentum for the industry at a time when supply chain shortages and slow-moving energy projects are already creating some headwinds. Reed Albergotti, semafor.com, 22 May 2026 Travel disruptions and looming severe weather also threaten to derail the unofficial start to summer. Holly Yan, CNN Money, 22 May 2026 Race dirt bikes long enough, and a mistake here or there can derail a season for any rider. Maury Brown, Forbes.com, 22 May 2026 Judges up and down the ladder must make clear that there will be consequences for disregarding their orders, and act on that clarity; so far, the limited number of contempt proceedings have run into procedural walls or been derailed by appellate courts. New York Daily News Editorial Board, New York Daily News, 22 May 2026 See All Example Sentences for derail

Word History

Etymology

French dérailler to throw off the track, from dé- de- + rail, from English

First Known Use

1850, in the meaning defined at transitive sense 1

Time Traveler
The first known use of derail was in 1850

Browse Nearby Words

Cite this Entry

“Derail.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/derail. Accessed 28 May. 2026.

Kids Definition

derail

verb
de·​rail di-ˈrā(ə)l How to pronounce derail (audio)
: to cause to run off the rails
a train derailed by heavy snow
derailment noun

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