derail

Etymology

It is borrowed from French dérailler (“to go off the rails”),^{[2][3][4][5][6][7]} formed from dé- (“off, away”) and rail,^[2][4][8][9] which French had itself borrowed from the English noun rail.^[4][7][10] The OED notes that the French verb is in Bescherelle's dictionary of 1845 and was admitted by the Académie française in 1878.^[2]

Earliest recorded meaning

Both to run off the rails and to make a train run off them: 1850, in Dionysius Lardner's Railway Economy.^[2][3][7]

Semantic evolution

According to the OED, the word was introduced from French about 1850 but seems to have come into general use first in the United States,^[2] and Weekley also says it was adopted there earlier than in Britain.^[11] From 1889 the verb meant to thwart a plan or proceeding by throwing it off course.^[2] By 1891 it could also mean to turn a person aside, or to confound someone.^[2] In American college slang of the 1920s derail was also a noun for an unpopular student.^[12] In railway use the noun derail is a device that guides cars off the rails at chosen points to prevent a collision.^[7][13]

Timeline

• 1850 – to run off the rails; to make a train leave the rails.^[2][3]
• 1889 – to disrupt or thwart a plan or activity.^[2]
• 1891 – to divert a person from a purpose.^[2]
• 1927 – noun, in American campus slang, an unpopular student.^[12]

Meanings

Verb

1. To cause a train or tram to leave its rails: A fallen tree derailed the night freight.^[13][7][2]
2. Of a train, to run off the rails.^[13][2][9]
3. To throw a plan, process or person off course; to disrupt or thwart: The scandal derailed her campaign.^[7][2]

Noun

1. A device that throws railway cars or locomotives off the track at a chosen point to avoid a collision; also called a derailer.^[7][13]

Word family

• derailment

Related words

• rail
• railway
• railroad
• derailleur

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
5. ^ Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
6. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
7. ^ a b c d e f g Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
8. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
9. ^ a b Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
10. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
11. ^ Weekley, Ernest (1921), An Etymological Dictionary of Modern English, London: John Murray
12. ^ a b Green, Jonathon (2010), Green's Dictionary of Slang, London: Chambers; digital ed. 2016–, https://greensdictofslang.com
13. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins