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
Carlos Kosienski/Sipa USA via Reuters The basic training facility for the Air Force in San Antonio, Texas, is experiencing a flu outbreak following the end of mandatory vaccination for all service members.
—
Luis Martinez, ABC News, 18 June 2026
The outbreak is suspected to have started several weeks before it was officially confirmed on May 15 and is caused by the rare Bundibugyo virus, which authorities were not testing for in the early days.
—Evie Carrick, Travel + Leisure, 18 June 2026
The more common Zaire virus, for which there is a vaccine, was responsible for most of Congo’s past 16 outbreaks of the disease.
—Wilson McMakin, Los Angeles Times, 18 June 2026
Mozambique said five of its citizens were killed in outbreaks of violence at the end of May, and Ghana has arranged flights for hundreds of its citizens to exit South Africa.
—Jasmin Malik Chua, Footwear News, 18 June 2026
See All Example Sentences for outbreak
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Luis Martinez, ABC News, 18 June 2026
The outbreak is suspected to have started several weeks before it was officially confirmed on May 15 and is caused by the rare Bundibugyo virus, which authorities were not testing for in the early days.
—Evie Carrick, Travel + Leisure, 18 June 2026
The more common Zaire virus, for which there is a vaccine, was responsible for most of Congo’s past 16 outbreaks of the disease.
—Wilson McMakin, Los Angeles Times, 18 June 2026
Mozambique said five of its citizens were killed in outbreaks of violence at the end of May, and Ghana has arranged flights for hundreds of its citizens to exit South Africa.
—Jasmin Malik Chua, Footwear News, 18 June 2026
See All Example Sentences for outbreak
Cite this Entry
“Outbreak.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/outbreak. Accessed 25 Jun. 2026.
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
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