from The American Heritage® Dictionary of the English Language, 4th Edition
- transitive v. To run or cause to run off the rails.
- transitive v. To come or bring to a sudden halt: a campaign derailed by lack of funds; a policy that derailed under the new administration.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A device placed on railway tracks causing a train to derail.
- v. To cause to come off the tracks.
- v. To come off the tracks.
- v. To deviate from the previous course or direction.
- v. To cause to deviate from a set course or direction.
from the GNU version of the Collaborative International Dictionary of English
- transitive v. To cause to run off from the rails of a railroad, as a locomotive.
from The Century Dictionary and Cyclopedia
- To cause to leave the rails or run off the track, as a railroad-train: as, the engine was derailed at the crossing.
- To run off the track or rails.
- n. In railroading, a switch which is designed to divert or throw a train or car from the track or to stop its further progress.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- v. cause to run off the tracks
- v. run off or leave the rails
French dérailler : dé-, off (from Old French de-; see de-) + rail, rail (from English; see rail1).(American Heritage® Dictionary of the English Language, Fourth Edition)
From de- + rail. (Wiktionary)