A more thorough explanation:

Willfully is an adverb that refers to doing something intentionally, purposefully, and stubbornly.

• He willfully drove the car into the crowd on the sidewalk.
• She willfully left the dangerous substances on the property.

In the first example, the driver intentionally and stubbornly drove the car into the crowd on the sidewalk. In the second example, the person purposefully left dangerous substances on the property, knowing the potential harm it could cause.

Another example could be: "He willfully ignored the warning signs and entered the restricted area."

This example illustrates that the person intentionally and stubbornly ignored the warning signs and entered the restricted area, despite the potential consequences.