What term indicates a failure to act timely to prevent an event?

The term that best indicates a failure to act timely in order to prevent an event is "forestall." This term specifically means to prevent something by taking action ahead of time. When you forestall an event, you are effectively mitigating its potential occurrence or impact through timely intervention. This proactive approach highlights the importance of acting within a suitable timeframe to avoid negative outcomes.

In contrast, other terms provided may have different connotations that do not align with the concept of timely prevention. "Mismanage" refers to improper handling or administration, which may not necessarily involve timeliness. "Neglect" implies a failure to care for something or someone and can encompass a broader range of inactions, not strictly the timely aspect. "Delay" suggests a postponement in action but does not inherently convey the proactive effort necessary to prevent an event from occurring.

Thus, "forestall" is the most appropriate choice as it captures the essence of taking timely action to ensure an event does not transpire.