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

• 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

And while the outbreak is concentrated in the neighborhood of Central Harlem, in recent weeks cases have also been identified in Michigan. —Juan Carlos Castillo, Freep.com, 7 Aug. 2025

The outbreak was first detected on July 25, with officials reporting 22 cases. —Jessica Schladebeck, New York Daily News, 6 Aug. 2025

Health officials say the outbreak has since spread to Hong Kong and Macao, as well as Hunan province, more than 400 miles north. —Vanessa Etienne, People.com, 6 Aug. 2025

The outbreak is localized in five New York City ZIP codes: 10027, 10030, 10035, 10037 and 10039. —Zachary Folk, Forbes.com, 6 Aug. 2025

Word History

First Known Use

1562, in the meaning defined at sense 1a

Rhymes for outbreak

• awake
• backache
• beefsteak
• betake
• cheesecake
• cupcake
• daybreak
• earthquake
• eastlake
• forsake
• 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