epidemic
1. [ adjective ] (especially of medicine) of disease or anything resembling a disease; attacking or affecting many individuals in a community or a population simultaneously
Examples:

"an epidemic outbreak of influenza"

Related terms: endemic endemic ecdemic medicine pestilent epizootic pandemic epiphytotic
2. [ noun ] (medicine) a widespread outbreak of an infectious disease; many people are infected at the same time
Related terms: outbreak pandemic
Similar spelling:   Epidendrum