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

After the train derails in a tunnel, palace staff begin evacuating — but moments later, a horrifying explosion kills Camilla’s private secretary, Sir Peregrine Greaves. —Simon Perry, PEOPLE, 26 Nov. 2025

Mashed potatoes seem like one of the simplest comfort foods to prepare, but the truth is there are a few key pitfalls that can quickly derail your efforts. —Katie Rosenhouse, Southern Living, 26 Nov. 2025

The host tried to wrap up their interview, while acknowledging that their entire conversation had been completely derailed by Beckinsale’s egg-citing development. —Emlyn Travis, Entertainment Weekly, 25 Nov. 2025

Brett Ratner, who directed the first three installments before his career was derailed in 2017 by #MeToo allegations, is returning to direct the fourth film. —Rebecca Rubin, Variety, 25 Nov. 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

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