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

Health officials are still investigating what caused the outbreak of more than 4,000 cases of cyclosporiasis, mostly reported in Michigan and surrounding states. — Kendall Staton, Washington Post, 17 July 2026

The outbreak, which was declared underway only two months ago, is the third largest on record and has grown at a faster rate than previous outbreaks. — Helen Branswell, STAT, 16 July 2026

Getting to the source of the outbreak has been difficult, as the incubation period for the parasite to make a person sick can be up to two weeks. — Erika Edwards, NBC news, 16 July 2026

The outbreak, which began in Michigan, has been most severe in the midwest, within southeast Michigan, Ohio, Kentucky, and West Virginia. — Nikki McCann Ramirez, Rolling Stone, 16 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