1850 (Dionysius Lardner, "Railway Economy"), in both transitive and intransitive senses, "cause to leave the rails or run off the tracks; to run off the rails or tracks," from French dérailler "to go off the rails," from de- (see de-) + railler (see rail (n.1)). Related: Derailed; derailing.
they had planned to derail the trains that carried atomic waste
the train derailed because a cow was standing on the tracks
deputize
deputy
*der-
deracialize
deracinate
derail
derailleur
derailment
derange
deranged
derangement
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