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

The outcome gives House Republicans — who had a 217 to 214 majority leading up to Fuller's victory — another seat as any one defection has threatened to derail their legislative agenda in recent months. —Caitlin Yilek, CBS News, 8 Apr. 2026

This one, coming off the back of two hugely disappointing, trophy-ending, and potentially derailing defeats, was one of their best of the season. —Tim Spiers, New York Times, 8 Apr. 2026

The most successful and lucrative family vlogs are indiscreet almost by definition—and yet the wrong kind of indiscretion can derail the whole gravy train. —Jessica Winter, New Yorker, 7 Apr. 2026

Ashcraft had impressed until an injury derailed his spring. —Ryan Kartje, Los Angeles Times, 6 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