outbreak
noun
out·break
ˈau̇t-ˌbrāk 
1
a
: a sudden or violent increase in activity or currency
the outbreak of war
b
: a sudden rise in the incidence of a disease
an outbreak of measles
c
: a sudden increase in numbers of a harmful organism and especially an insect within a particular area
an outbreak of locusts
2
Examples of outbreak in a Sentence
there was an immediate outbreak of paper shuffling and a pretense of work when the supervisor passed through the room
the government quelled the outbreak with ruthless efficiency
Recent Examples on the Web
Born nine years before the first polio vaccine, the president remembers the fear that gripped families as outbreaks spread during his early childhood — and has spoken of friends who were affected.
—
Robert Goldberg, Boston Herald, 28 Nov. 2025
The surging number of measles cases around the world is a stark warning sign that outbreaks of other vaccine-preventable diseases could be next, the World Health Organization warned Friday.
—Erika Edwards, NBC news, 28 Nov. 2025
Fifty-nine countries reported large or disruptive measles outbreaks last year, almost triple the number reported in 2021.
—Asuka Koda, CNN Money, 28 Nov. 2025
At the same time, local and state public‑health departments employ about 239,000 people nationwide, yet years of underinvestment, burnout and long-standing vacancies already leave many health departments unable to maintain basic services—from maternal-health home visiting to outbreak investigation.
—MSNBC Newsweek, 28 Nov. 2025
See All Example Sentences for outbreak
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Robert Goldberg, Boston Herald, 28 Nov. 2025
The surging number of measles cases around the world is a stark warning sign that outbreaks of other vaccine-preventable diseases could be next, the World Health Organization warned Friday.
—Erika Edwards, NBC news, 28 Nov. 2025
Fifty-nine countries reported large or disruptive measles outbreaks last year, almost triple the number reported in 2021.
—Asuka Koda, CNN Money, 28 Nov. 2025
At the same time, local and state public‑health departments employ about 239,000 people nationwide, yet years of underinvestment, burnout and long-standing vacancies already leave many health departments unable to maintain basic services—from maternal-health home visiting to outbreak investigation.
—MSNBC Newsweek, 28 Nov. 2025
See All Example Sentences for outbreak
Cite this Entry
“Outbreak.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/outbreak. Accessed 2 Dec. 2025.
Copy CitationKids Definition
outbreak
noun
out·break
ˈau̇t-ˌbrāk
1
: a sudden increase in activity, use, or acceptance
the outbreak of war
2
: something (as an epidemic or revolution) that breaks out
an outbreak of measles
Medical Definition
outbreak
noun
out·break
ˈau̇t-ˌbrāk
1
: a sudden rise in the incidence of a disease
an outbreak of measles
2
: a sudden increase in numbers of a harmful organism and especially an insect within a particular area
an outbreak of locusts
Love words? Need even more definitions?
Merriam-Webster unabridged
Share