Final answer:
Foreseeability, according to Willard, is the principle that teachers and principals can take action if they have information indicating a significant disruption may result from student speech.
Step-by-step explanation:
Foreseeability, according to Willard, is the principle that teachers and principals do not have to wait until incidents happen. If they have information indicating a significant disruption may result from student speech, they can take action. This means that educators have the authority to intervene and address potential issues before they escalate.