Epidemic (noun)

1. A widespread occurrence of an infectious disease in a community at a particular time.
2. A sudden increase in the number of cases of a disease above what is normally expected in that population.

Origin:

From latin epidēmius ("prevalent among a people"), from greek epidēmios, from epidēmos ("among the people"), from epi ("among") + dēmos ("people").

Examples:

1. The flu is currently an epidemic in many parts of the country.
2. The COVID-19 pandemic is an epidemic of global proportions.
3. The plague was an epidemic that killed millions of people in the Middle Ages.
4. The epidemic spread rapidly through the city.
5. The government is taking steps to contain the epidemic and prevent further spread of the disease.