- 1(of a train) to leave the track; to make a train do this The train derailed and plunged into the river. derail something
- 2(figurative) This latest incident could derail the peace process.
NAmE//dɪˈreɪl//[intransitive, transitive]Verb Forms present simple I / you / we / they derail
he / she / it derails
past simple derailed
-ing form derailing
derailmentjump to other results
noun [countable, uncountable]