Derail

 To "derail a plan" means to cause a plan to fail or to disrupt its progress significantly. The metaphor comes from the idea of a train being derailed, meaning it goes off its tracks and cannot continue its journey as intended. Here are some contexts using this phrase:

1. **Workplace Context**:

   - "The unexpected budget cuts have the potential to derail our expansion plans."

   - "A sudden change in market conditions could derail the company's new product launch."

2. **Personal Context**:

   - "Her illness derailed their vacation plans, forcing them to cancel the trip."

   - "His lack of preparation derailed his plan to pass the certification exam."

3. **Political Context**:

   - "The scandal threatened to derail the candidate's campaign for re-election."

   - "Opposition from key stakeholders might derail the government's reform plans."

In each of these examples, "derail" is used to describe the disruption or failure of a plan or intention.