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
For the past year, there have been many animal outbreaks in a variety of wild and domestic animals, especially among birds and cattle.
—
Ron Barrett, The Conversation, 31 Mar. 2025
After 10 years of war, Yemen is gripped by malnutrition, disease outbreaks, lack of access to health care and other urgent services, and other life-threatening risks to the most vulnerable — all evidence of a full-scale humanitarian crisis.
—Sarah Ferguson, Forbes.com, 31 Mar. 2025
There have been five outbreaks, defined as three or more related cases, reported in 2025 and 16 last year.
—Jonathan Vigliotti, CBS News, 31 Mar. 2025
In addition to fire contamination, California’s sea life is also under threat from an outbreak of domoic acid, a neurotoxin released by some marine algae species.
—Corinne Purtill, Los Angeles Times, 28 Mar. 2025
See All Example Sentences for outbreak
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Ron Barrett, The Conversation, 31 Mar. 2025
After 10 years of war, Yemen is gripped by malnutrition, disease outbreaks, lack of access to health care and other urgent services, and other life-threatening risks to the most vulnerable — all evidence of a full-scale humanitarian crisis.
—Sarah Ferguson, Forbes.com, 31 Mar. 2025
There have been five outbreaks, defined as three or more related cases, reported in 2025 and 16 last year.
—Jonathan Vigliotti, CBS News, 31 Mar. 2025
In addition to fire contamination, California’s sea life is also under threat from an outbreak of domoic acid, a neurotoxin released by some marine algae species.
—Corinne Purtill, Los Angeles Times, 28 Mar. 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 5 Apr. 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
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