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
Manage insect vectors by reducing weeds in and around the garden and treating pests when outbreaks occur.
—
Kim Toscano, Southern Living, 29 May 2026
The drop was due to the outbreak of the Iran war, which sparked a stock selloff, according to Kirsten Hunter Peterson, vice president of workplace thought leadership at Fidelity Investments.
—Jessica Dickler, CNBC, 28 May 2026
El Nino meets Iran To make matters worse, 2026’s Super El Nino hits right as Asia grapples with a fuel crisis sparked by the outbreak of the Iran war earlier this year.
—Angelica Ang, Fortune, 28 May 2026
Mongbwalu, a once-thriving gold-mining town in eastern DRC, is now emerging as the epicenter of the country’s latest Ebola outbreak.
—Emmet Livingstone, NPR, 28 May 2026
See All Example Sentences for outbreak
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Kim Toscano, Southern Living, 29 May 2026
The drop was due to the outbreak of the Iran war, which sparked a stock selloff, according to Kirsten Hunter Peterson, vice president of workplace thought leadership at Fidelity Investments.
—Jessica Dickler, CNBC, 28 May 2026
El Nino meets Iran To make matters worse, 2026’s Super El Nino hits right as Asia grapples with a fuel crisis sparked by the outbreak of the Iran war earlier this year.
—Angelica Ang, Fortune, 28 May 2026
Mongbwalu, a once-thriving gold-mining town in eastern DRC, is now emerging as the epicenter of the country’s latest Ebola outbreak.
—Emmet Livingstone, NPR, 28 May 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 2 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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