epidemic

Etymology

From French épidémique, from épidémie, from Medieval Latin epidēmia, reanalysis of plural Late Latin epidēmia, from Ancient Greek ἐπιδήμιος (epidḗmios), from ἐπί (epí, “upon”) + δῆμος (dêmos, “people”). Surface analysis epi- (“on”) + demic (“of the people”).

noun

1. A widespread disease that affects many individuals in a population.
   At that time, the city [Christiania, now Oslo] was in the grip of a cholera epidemic, and victims were dying at the rate of 60 a day. Bradshaw contracted the disease, and died on September 6 [1853]. 1950 January, “Notes and News: George Bradshaw's Grave”, in Railway Magazine, pages 61–62
2. (epidemiology) An occurrence of a disease or disorder in a population at a frequency higher than that expected in a given time period; an episode of outbreak and subsequent high prevalence.
3. (figurative) The spreading of an idea or belief amongst a population.

adj

1. Like or having to do with an epidemic; widespread.
   Epidemic hysteria occurred upon the incumbent’s reelection.
   [In] May, there was, at London and in its neighbourhood, a disease very epidemic, though not fatal, which had some time before been very prevalent both in Italy and Germany. 1852, Annals of influenza or epidemic catarrhal fever in Great Britain, page 76
   The major reason for such an examination was to determine if any patterns uncovered seemed to be more epidemic than endemic. 1986, Gerald F. Pyle, The Diffusion of Influenza: Patterns and Paradigms, page 123
   This proportion increased about 5% from 1988 to 1992—hardly a change of epidemic proportions. 2003, James C. Howell, Preventing & Reducing Juvenile Delinquency: A Comprehensive Framework, SAGE Publications, page 19
   This was the stagecoach holdup, and while these encounters were not as epidemic as we like to remember, nonetheless there were numerous bands of "road agents" who lay by the roadside in wait for passengers. 2013, Frederick Allen, A Decent, Orderly Lynching: The Montana Vigilantes, page 8