derail

verb

de·​rail di-ˈrāl 

dē-

derailed; derailing; derails

transitive verb

1

: to cause to run off the rails

2

a

: to obstruct the progress of : frustrate

security problems derailed the tour

b

: to upset the stability or composure of

divorce … can seriously derail an employee

—Joanne Gordon

intransitive verb

: to leave the rails

derailment

di-ˈrāl-mənt 

dē-

noun

Synonyms

• agitate
• ail
• alarm
• alarum
• bother
• concern
• discomfort
• discompose
• dismay
• disquiet
• distemper
• distract
• distress
• disturb
• exercise
• flurry
• frazzle
• freak (out)
• fuss
• hagride
• perturb
• undo
• unhinge
• unsettle
• upset
• weird out
• worry

Examples of derail in a Sentence

The train derailed in heavy snow.

The train was derailed by heavy snow.

Recent Examples on the Web

Just ask fellow nominee Karla Sofía Gascón, star of Netflix’s Emilia Pérez, who complained of their online bullying before her own racist tweets derailed her campaign. —Seth Abramovitch, The Hollywood Reporter, 15 Feb. 2025

Fultz’s career was nearly derailed by a severe shoulder injury that was diagnosed as thoracic outlet syndrome, which affects nerves between the neck and shoulder. —Jason Anderson, Sacramento Bee, 14 Feb. 2025

Engelmayer has a long history of derailing Trump’s agenda. —Robert Schmad, Washington Examiner - Political News and Conservative Analysis About Congress, the President, and the Federal Government, 13 Feb. 2025

And a familiar divide between House and Senate Republicans is threatening to derail meaningful reform. —Matthew Kelly, Kansas City Star, 11 Feb. 2025

Word History

Etymology

French dérailler to throw off the track, from dé- de- + rail, from English

First Known Use

1850, in the meaning defined at transitive sense 1

Kids Definition

derail

verb

de·​rail di-ˈrā(ə)l 

: to cause to run off the rails

a train derailed by heavy snow

derailment

-mənt 

noun