What is the act of attempting to overthrow the government called?

The act of attempting to overthrow the government is most accurately described as treason. Treason specifically involves acts that betray one’s own country, particularly through engaging in war against it or giving aid and comfort to its enemies. This definition reflects the gravity of such actions under law, as it not only signifies a direct attack on the government's authority but also poses a fundamental risk to the very existence of the nation.

While concepts like subversion, insurrection, and sedition are related to anti-government activities, they do not precisely capture the full scope of treason. Subversion generally refers to actions intended to undermine the power and authority of an established system, insurrection describes an uprising against authority, and sedition often relates to inciting rebellion against governmental authority. Each of these terms carries distinct connotations and legal implications but does not equate to the severe classification and legal consequences associated with treason. Thus, treason stands out as the most applicable term when discussing attempts to completely overthrow or significantly undermine a government’s legitimacy.