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

One of the most painful things about this disease is knowing that promising treatments are emerging, but funding barriers and manufacturing and procedural slow-downs continue to derail progress. —Elise Esposito, Boston Herald, 29 May 2026

Throughout the finale, Niall continues to struggle with his identity, using chemsex parties as a crutch that are slowly but surely derailing his life. —Barry Levitt, Time, 29 May 2026

To be sure, Amazon's use of multiple launch providers reduces the risk that any single launch failure derails its plans. —Paulina Likos,kevin Stankiewicz, CNBC, 29 May 2026

But fierce competition, personal drama and a scandal from the past threaten to derail the dream before the summer sets. —Benjamin Vanhoose, PEOPLE, 28 May 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