Intentional; not accidental; voluntary; designed.
There is no precise definition of the term willful because its meaning largely depends on the context in which it appears. It generally signifies a sense of the intentional as opposed to the inadvertent, the deliberate as opposed to the unplanned, and the voluntary as opposed to the compelled. After centuries of court cases, it has
no single meaning, whether as an adjective (willful) or an adverb (willfully).
Statutes and case law have adapted the term willful to the particular circumstances of action and inaction peculiar to specific areas of the law, including TORT LAW, CRIMINAL LAW, WORKERS' COMPENSATION, and UNEMPLOYMENT COMPENSATION. A willful violation, for example, may mean a deliberate intent to violate the law, an intent to perform an act that the law forbids, an intent to refrain from performing an act that the law requires, an indifference to whether or not action or inaction violates the law, or some other variant.
In criminal-law statutes, willfully ordinarily means with a bad purpose or criminal intent, particularly if the proscribed act is mala in se (an evil in itself, intrinsically wrong) or involves moral turpitude. For example, willful murder is the unlawful killing of another individual without any excuse or MITIGATING CIRCUMSTANCES. If the forbidden act is not wrong in itself, such as driving over the speed limit, willfully is used to mean intentionally, purposefully, or knowingly.