If there is an outbreak of something unpleasant, such as violence or a disease, it suddenly starts to happen.
例句
The four-day festival ended a day early after an outbreak of violence involving hundreds of youths.一场有数百名年轻人卷入的暴力活动发生后,为期4天的节庆活动被迫提前一天结束。...the outbreak of war in the Middle East...中东战争的爆发
英汉词典释义
n.
(暴力、疾病等坏事的)爆发,突然发生
An outbreak of typhoid followed.继而爆发了伤寒。At the outbreak of the war he lived in London.战争爆发时他住在伦敦。
英英词典释义
Noun
1. a sudden violent spontaneous occurrence (usually of some undesirable condition);