pestilence

Definitions:

Any contagious disease that is epidemic and mortal; anything pestilent, physically or morally.
- Nuttall's Standard dictionary of the English language. By Nuttall, P.Austin. Published 1914. (noun) (n.) (noun)
An infectious or contagious disease that is widespread and fatal.
- The Winston Simplified Dictionary. By William Dodge Lewis, Edgar Arthur Singer. Published 1919. (noun) (n.) (noun)
Any contagious and malignant or mortal disease; the plague; anything sweepingly destructive.
- Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874. (noun) (n.) (noun)
Any contagious deadly disease.
- The american dictionary of the english language. By Daniel Lyons. Published 1899. (noun) (n.) (noun)
Epidemic contagious disease; plague.
- The Clarendon dictionary. By William Hand Browne, Samuel Stehman Haldeman. Published 1894. (noun) (n.) (noun)

Usage examples:

The whole country might be devastated by a pestilence and the few survivors might lapse into anything.
- White Fire by John Oxenham
It was one of the worst years of that scourge of the South- the yellow fever- and to this dread pestilence he had fallen a victim.
- Popular Adventure Tales by Mayne Reid
In malignant scarlatina happily of infrequent occurrence, the child is struck down, as though its blood were poisoned, from the very first; and death takes place often within forty- eight hours, the rash appearing just sufficiently to stamp the nature of the pestilence which has proved so deadly.
- The Mother's Manual of Children's Diseases by Charles West, M.D.