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

Coal may be a readily available buffer for now, but the Iran war won’t derail the transition to cleaner energy. —Julius Cesar Trajano, Fortune, 24 Apr. 2026

Rwanda and Mozambique are the two sub-Saharan African countries most exposed to the Middle East war, the ratings agency S&P said, as surging fuel costs and disrupted trade routes threaten to derail fragile economic recoveries. —Tiisetso Motsoeneng, semafor.com, 24 Apr. 2026

Bromfield had nearly finished converting the 25,000-square-foot brick building to apartments when the pandemic derailed his work. —Don Stacom, Hartford Courant, 24 Apr. 2026

The building was closed in the immediate aftermath, but the rest of the plant remained operational, and the tornado did not derail the production launch, the company said. —Robert Channick, Chicago Tribune, 24 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