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

In fact, almost 60% of Gen Z and Millennials say social spending, which includes the occasional dining experience and vacation with friends, has derailed their financial plans, according to a 2025 survey from Ally. — Itzel Franco, CNBC, 21 Sep. 2026

Backed by the trade press, the studio heads and the officers of the Motion Picture Producers and Distributors of America banded together to orchestrate a full-court press to derail the Sinclair campaign and drag Merriam over the finish line. — Thomas Doherty, HollywoodReporter, 19 Sep. 2026

Mackert, a Western Illinois recruit who has had a huge start to the season, is going to do everything in his power to make sure adversity doesn’t derail the Celtics. — Steve Millar, Chicago Tribune, 18 Sep. 2026

The additional trial in adults 65 and older stems from a controversy that nearly derailed the vaccine’s approval. — Berkeley Lovelace Jr, NBC news, 18 Sep. 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