What is the definition of armed resistance to one's government or ruler?

The correct answer is rebellion, which is defined as an organized and often violent attempt by a group of people to change or overthrow the authority of their government or ruler. This can happen for a variety of reasons, including political, social, or economic grievances. Rebellions typically involve the mobilization of people and resources to challenge the existing power structure, and they can vary in scale from local uprisings to large-scale revolutions.

While the other options refer to related concepts, they do not adequately capture the specific idea of armed resistance against a government or ruler. Piracy refers to robbery or violence at sea, which does not directly relate to a challenge against a governing authority. Invasion implies an external entity entering a territory to conquer or impose control, rather than a domestic uprising. Insurgence is often used synonymously with rebellion, but it tends to denote a more spontaneous or unorganized uprising that may not necessarily have the broader goals associated with rebellion. Thus, rebellion is the most precise term for armed resistance to one's government or ruler.