Definition of "epidemic"

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 .

1950 January, “Notes and News: George Bradshaw's Grave”, in Railway Magazine, pages 61–62

Lord Avonleigh was at once liberated from his imprisonment, well prepared to be considered, and to consider himself, a martyr to the cause of loyalty; and as the services of the rich nobleman,...his claims to notice and favour were most graciously acknowledged. Accordingly, he returned to his seat in a little fever of royal devotedness—it was the fashionable epidemic; and who coming from Whitehall could be without it?

1834, L[etitia] E[lizabeth] L[andon], Francesca Carrara. […], volume III, London: Richard Bentley, […], (successor to Henry Colburn), pages 98–99

[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