Literally:
* To cause a train to leave the tracks. This is the most common and original meaning of the word, and it often signifies a disastrous event.
Figuratively:
* To disrupt or prevent something from continuing as planned. This meaning can be used for plans, projects, conversations, and even emotions. For example:
* "The unexpected rain derailed our picnic plans."
* "The sudden argument derailed the meeting."
* "His anger derailed his ability to think clearly."
In more specific contexts:
* To prevent someone from achieving their goals. This meaning is often used in relation to personal growth, development, or career advancement.
* "Her lack of confidence derailed her dream of becoming a singer."
In slang:
* To cause someone to lose control of their emotions. This usage is typically informal and often refers to a negative emotional response.
* "His rude comment derailed her, and she started crying."
Overall, "derail" implies a disruption, a failure to stay on track, or a sudden and unwanted shift in direction.