Webster's Revised Unabridged Dictionary · 1913

outbreak

outbreak , noun

1.
A bursting forth; eruption; insurrection; mutiny; revolt.
Mobs and outbreaks. — J. H. Newman
The flash and outbreak of a fiery mind. — Shakespeare
2.
A sudden beginning of a violent event; as, the outbreak of hostilities between ethnic groups.
3.
A sudden occurrence or manifestation; -- usually of disease or emotion, in one person or a group; as, an outbreak of measles among the students; he had an outbreak of shingles; an outbreak of nervousness in the mob.