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 of derail

• distract
• disturb
• bother
• worry
• alarm
• concern
• unsettle
• agitate
• anger

Examples of derail in a Sentence

The train derailed in heavy snow.

The train was derailed by heavy snow.

Recent Examples on the Web

But the troubled doctor has deeply affecting conversations about his mental health with colleagues like Langdon, which seem to derail his plan to potentially end his life at the end of his sabbatical motorcycle trip. —Bryan Alexander, USA Today, 17 Apr. 2026

Kennedy was widely tipped for America's top office until the Chappaquiddick incident in 1969 derailed his political career. —Richard Edwards, Space.com, 17 Apr. 2026

Markets are firmly optimistic and investors would hope the stock rally does not be derailed by geopolitics. —Lim Hui Jie, CNBC, 17 Apr. 2026

Mediators are pushing for a compromise on three main sticking points that derailed direct talks last weekend — Iran’s nuclear program, the Strait of Hormuz and compensation for wartime damages, according to a regional official involved in the mediation efforts. —ABC News, 16 Apr. 2026

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

Rhymes for derail

• airmail
• assail
• avail
• bewail
• blackmail
• cattail
• cocktail
• curtail
• detail
• dovetail
• email
• entail

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