English Reference
Noun

derailment

n. C / U
C1 Advanced US /dɪˈɹeɪɫmənt/ UK /dɪɹˈeɪlmənt/ de·rail·ment UK spelling derailments

n.the act of a train coming off its tracks, or a situation that stops a plan from moving forward. It can also describe a person's mind wandering away from the main topic.

n.the act of a train being forced off its rails; by extension, any event that prevents a process or plan from continuing as intended. Often used metaphorically to describe a loss of focus or a deviation from a logical argument.


SIMPLE

The heavy snow caused a derailment on the main line.

CONTEXTUAL

A sudden technical failure led to the derailment of the entire project, forcing the team to start over from scratch.

COMPLEX

The speaker's tendency to share personal anecdotes often resulted in a derailment of the central thesis, leaving the audience confused about the original argument.

Then our carriage jumped vertically upwards and we could tell it was a derailment.

The Guardian· 14 Aug 2026

Told as a memoir, with Mira looking back on the derailment of her life and chronicling society’s changing perceptions of agency and privilege, this literary thriller is a masterfully executed ace.

The Guardian· 14 Aug 2026
This entry
Level C1 · Advanced
Frequency Occasional
Updated