One who, or that which, derails. / Synonym of derail: A device placed on railway tracks in order to cause a train to derail.

plural of derailer

Capable of being derailed.

plural of derailing

Synonym of derailer: A device placed on railway tracks in order to cause a train to derail. / An instance of diverting a conversation or debate from its original topic.

(transitive) To cause to come off the tracks. / (intransitive) To come off the tracks. / (intransitive, figuratively) To deviate from the previous course or direction.

Third-person singular simple present indicative form of derail

present participle of derail

The act by which something is derailed.

simple past tense and past participle of derail