What does outbreak mean?
An outbreak is the sudden appearance or rapid increase of something, especially a disease, conflict, disturbance, or other disruptive condition. The word is especially common in public health reporting, where it describes a disease that appears among people in a particular place or period and may continue to spread. More broadly, it can refer to an eruption of violence, unrest, activity, or emotion. “Outbreak of violence” and “outbreak of disease” are established expressions, while the term generally carries a negative or cautionary connotation because outbreaks suggest disruption and potential danger. The word can also describe a sudden mass appearance of animals or plants, such as an outbreak of monarch butterflies. Although “outburst” sometimes appears nearby in meaning, an outbreak generally affects a wider group, place, or population, whereas an outburst is more often an individual or collective expression. In all its uses, the central idea is something emerging suddenly and often with striking or disruptive force.
nounA sudden occurrence or rapid increase of something, especially a disease, conflict, or other disruptive event. It can also refer to the sudden emergence of a swarm or mass appearance of animals or plants.
- A sudden occurrence or rapid spread of a disease or other harmful condition.
- A sudden eruption of conflict, violence, activity, or intense emotion.
- A sudden appearance or mass emergence of animals, insects, or plants.
"Health officials warned that the outbreak could spread rapidly through the community."
"The outbreak of influenza forced several schools to close for a week."
"There was an angry outburst after the referee awarded a controversial penalty."
"An outbreak of monarch butterflies transformed the meadow into a patchwork of orange and black."
A countable noun; use “outbreak” for a single event and “outbreaks” for multiple separate occurrences.
"Several outbreaks of the disease have been reported in different regions."
An outbreak makes disruption literal: something that had remained contained suddenly “breaks out.”
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does outbreak come from?
“Outbreak” was formed in the early 17th century from “out” and “break,” with the older sense referring to something bursting or breaking out. Its earliest uses could refer to an eruption, such as an outbreak of fire or violence, before the word became especially associated with epidemics. It shares its root with “break,” “breach,” “breakage,” and related forms derived from the Old English word brecan, meaning “to break, shatter, or burst.”
How outbreak is actually used
The term is most common for diseases and other serious public events. It is generally formal or journalistic and can suggest a problem that appears suddenly and may spread beyond its original location.
Easily confused with outbreak
An outbreak often develops over an area or population, whereas an outburst is usually a sudden expression of emotion or activity by an individual or group.
An eruption is often a violent or forceful occurrence, while an outbreak emphasizes the sudden appearance or rapid spread of a condition.