verb (used with object)
- to cause (a train, streetcar, etc.) to run off the rails of a track.
- to cause to fail or become deflected from a purpose; reduce or delay the chances for success or development of: Being drafted into the army derailed his career for two years.
verb (used without object)
- (of a train, streetcar, etc.) to run off the rails of a track.
- to become derailed; go astray.
noun
- a track device for derailing rolling stock in an emergency.
verb
- to go or cause to go off the rails, as a train, tram, etc
noun
- Also called: derailer mainly US a device designed to make rolling stock or locomotives leave the rails to avoid a collision or accident
1850, in both transitive and intransitive senses, from French dérailler “to go off the rails,” from de- (see de-) + railler (see rail (n.1)). In general use first in U.S. Related: Derailed; derailing.