Derail is a verb that means to cause something to go off course or deviate from its intended path. Some synonyms for derails include obstructs, hinders, impedes, interrupts, sabotages, frustrates, and disrupts. When a plan or project is derailed, it can cause delays, setbacks, or even failure. Other synonyms that can be used for derails include throws off, sidetracks, deters, diverts, or deranges. These words all describe when an obstacle or issue arises that distracts or prevents progress from being made. Whether it's a train that gets derailed or a project that gets thrown off course, synonyms for derails can help describe situations where things don't go as planned.