IPA: /ˈaʊtˌbreɪk/
KK: /ˈaʊtˌbreɪk/
A sudden occurrence or increase of something, especially a disease or a problem.
The outbreak of the flu this winter has affected many people in the community.
Outbreak is formed from "out-" (meaning outside or outward) and "break" (from Old English "brecan", meaning to break). The word describes a breaking out or emergence of something, typically used in the context of diseases or events occurring suddenly and extensively.
Think of something that 'breaks out' from the 'outside' — that's why an outbreak refers to a sudden emergence of something, like a disease.