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

: insurrection, revolt

Synonyms of outbreak

• flurry
• burst
• outburst

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

Renner was referring to the allegation the National Institute of Health helped fund gain of function research, which tests how altered viruses act in the real world, at a lab in Wuhan, the Chinese city that saw the first outbreak of COVID-19. — Gray Rohrer, Miami Herald, 31 July 2026

During the height of the 2025 outbreak, Kennedy somewhat pulled back from anti-vaccine messaging and encouraged inoculation against measles. — Janet Loehrke, USA Today, 30 July 2026

The Coalition for Epidemic Preparedness Innovations is financing the first clinical trials for an experimental jab to control the outbreak, though production is not expected until year-end. — Jeronimo Gonzalez, semafor.com, 30 July 2026

While smallpox is no longer a daily concern, the latest DNA discoveries can help public health officials, biologists, and epidemiologists prepare for and fight future disease outbreaks. — Andrew Paul, Popular Science, 30 July 2026

Word History

First Known Use

1562, in the meaning defined at sense 1a

Rhymes for outbreak

• awake
• backache
• beefsteak
• betake
• cheesecake
• cupcake
• daybreak
• earthquake
• forsake
• gouache
• handshake
• headache

Kids 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