A pandemic is an outbreak of a contagious disease that affects a large geographic area, often spreading across multiple countries or continents. Unlike epidemics which are localized outbreaks, pandemics have global implications.
Related terms
Epidemic: An outbreak of an infectious disease that affects a specific community or region.
Influenza (flu) pandemic: A global outbreak of influenza viruses with significant mortality and morbidity.
Contagion: The transmission or spread of an infectious disease from one individual to another.