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

Extremely hot, dry conditions can lead to outbreaks of spider mites, though damage seldom requires treatment. —Kim Toscano, Southern Living, 22 Feb. 2026

Hospitalization rates can vary greatly by a measles outbreak’s location and who is getting infected. —Jennifer Berry Hawes, CNN Money, 21 Feb. 2026

Large outbreaks continue to grow in Utah, Arizona and, most notably, South Carolina, where the virus has been spreading since the fall. —Erika Edwards, NBC news, 21 Feb. 2026

Meanwhile in Florida, a small private college in Collier County is in the early days of a measles outbreak, with more than 60 cases reported as of Friday. —The Orlando Sentinel, 21 Feb. 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
• 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