What term describes an infectious disease that spreads over a wide geographic area, often globally?

A pandemic is defined as an infectious disease that spreads across a large geographic area, often affecting multiple countries or continents. The key characteristic of a pandemic is its widespread nature, which allows it to impact a significant portion of the global population. This term is typically used when the disease has reached a level of contagion and impact that goes beyond the confines of local or regional outbreaks.

In the context of the other terms, an epidemic refers to an increase in disease cases within a specific area or population, but it does not have the global reach that characterizes a pandemic. Endemic refers to a disease or condition that is regularly found and consistently present within a particular geographic area or population, so it does not involve the widespread dispersion seen in pandemics. An outbreak is generally a more limited increase in disease cases, typically localized or focused on a community or region, and does not reflect the expansive spread noted in pandemics.

Thus, understanding these distinctions clarifies why the term "pandemic" accurately describes the situation of an infectious disease spreading globally.