A pandemic is an outbreak of a disease that affects many people all over the world.
When we say there's been a pandemic, it usually means that a contagious illness has spread so far and wide that almost every country on the globe is dealing with it. Just think about what happened in 2020 with COVID-19 – it was everywhere, from small towns to big cities, affecting people of all ages and backgrounds. When there's a pandemic, governments often have to take drastic measures to slow down its spread, like closing schools or imposing travel restrictions.
(epidemiology) Of a disease: epidemic over a wide geographical area and affecting a large proportion of the population; also, of or pertaining to a disease of this nature.
Example: The chaotic breakdown of public health as World War I dragged on is widely recognized as exacerbating the disease burden of the pandemic outbreak of influenza in 1918.
