- The definition of an outbreak is a sudden increase, outburst or riot.
An example of an outbreak is five cases of whooping cough increasing to fifty cases overnight.
- a breaking out; sudden occurrence, as of disease or war
- an insurrection or riot
Used by arrangement with John Wiley & Sons, Inc.
- A sudden increase: an outbreak of influenza.
- A sudden eruption; an outburst: “an outbreak of strikes, violent agitation, and arrests” (Samuel Chew).