epidemicity ep·i·de·mic·i·ty (ěp'ĭ-də-mĭs'ĭ-tē)
The ability to spread from one host to others; the state of being epidemic.
epidemic ep·i·dem·ic (ěp'ĭ-děm'ĭk) or ep·i·dem·i·cal (-ĭ-kəl)
Spreading rapidly and extensively by infection and affecting many individuals in an area or a population at the same time, as of a disease or illness. n.
An outbreak or unusually high occurrence of a disease or illness in a population or area.
An outbreak of a disease or illness that spreads rapidly among individuals in an area or population at the same time. See also endemic, pandemic.