Definition of derail in English:

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Pronunciation: /dɪˈreɪl/


[with object]
1Cause (a train or tram) to leave its tracks accidentally: a train was derailed after it collided with a herd of cattle
More example sentences
  • A strong earthquake shook northwest Japan yesterday, destroying homes, derailing a bullet train and cutting water and power supplies.
  • She said there were two big questions that needed to be answered with urgency: how the car came to be on the track at the time and how the train was derailed in such a catastrophic way.
  • The train was not derailed and remained on the track.
1.1 [no object] (Of a train or tram) accidentally leave the tracks: the trams had a tendency to derail on sharp corners
More example sentences
  • The train car derailed, and a crater was left in the track bed.
  • The train then derailed into the path of an oncoming freight train.
  • Officials say at least three of the train's cars derailed.
1.2 [with object] Obstruct (a process) by diverting it from its intended course: the plot is seen by some as an attempt to derail the negotiations
More example sentences
  • Which leads to another question: Was the robbery intended to derail the peace process?
  • He makes an excellent case that it was created in ‘an obvious attempt to derail the peace process.’
  • Both sides said they are committed to peace talks and analysts say the blast could impede but not derail the process.


Mid 19th century: from French dérailler, from dé- (expressing removal) + rail 'rail'.

For editors and proofreaders

Line breaks: de¦rail

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