derail verb definition in Train and bus travel topic from the Oxford Advanced Learner's Dictionary

derail

 verb: Train and bus travel topic
(of a train) to leave the track; to make a train do this The train derailed and plunged into the river. derail something (figurative) This latest incident could derail the peace process. It is claims of financial irregularities which could ultimately derail his campaign. The company’s plans were initially derailed by problems with licence agreements.