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

• 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 May 2018, one of the funicular’s cars derailed due to a serious maintenance failure of its wheels, although the car did not overturn and no one was injured, according to Público, a Portuguese daily national newspaper. —Miranda Jeyaretnam, Time, 4 Sep. 2025

At least 15 people have been killed and 18 were injured after a funicular railway in Lisbon, Portugal, derailed on Wednesday. —Hannah Parry, MSNBC Newsweek, 4 Sep. 2025

Despite opposition from Democrats — including a quorum break that derailed an earlier special session — Republican lawmakers successfully ushered in a new congressional map that positions Republicans to pick up five seats in Congress. —Fort Worth Star-Telegram, 4 Sep. 2025

Syria’s new government must quash the sectarian violence that threatens to derail the nation’s post-Assad progress. —semafor.com, 3 Sep. 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