Treason

Definition
Treason is the crime that covers some of the more serious acts of betrayal of one's sovereign or nation. Historically, treason also covered the murder of specific social superiors, such as the murder of a husband by his wife. Treason against the king was known as high treason and treason against a lesser superior was petit treason. A person who commits treason is known in law as a traitor.

Oran's Dictionary of the Law (1983) defines "treason" as

"[a]...citizen's actions to to help a foreign government overthrow, make war against, or seriously injure the [parent nation]."

In many nations, it is also often considered treason to attempt or conspire to overthrow the government, even if no foreign country is aided or involved by such an endeavor.