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

Republican Senators Mitch McConnell of Kentucky, Susan Collins of Maine, Todd Young of Indiana and Jerry Moran of Kansas are among those who could derail Gabbard's nomination by voting to block her confirmation. —David Faris, Newsweek, 2 Feb. 2025

Alia Shawkat stars as an aspiring actress in a military role-playing facility who falls in love with a soldier (Callum Turner) cast as an insurgent, but their unsimulated emotions threaten to derail the performance. —Anthony D'alessandro, Deadline, 31 Jan. 2025

The Trump administration's freeze on foreign aid threatens to derail global efforts to fight disease outbreaks, counter terrorism, and provide humanitarian assistance to people affected by conflict. —Ivana Saric, Axios, 31 Jan. 2025

Why Dems are fearful of Trump's pick to lead the FBI — and their strategy to derail him. —Fox News, 30 Jan. 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