WordNet: eruption, irruption, outbreak

a sudden violent spontaneous occurrence (usually of some undesirable condition); "the outbreak of hostilities"

• hypernym happening, natural event, occurrence, occurrent

• hyponym epidemic

• hyponym recrudescence

eruption

• (englanti) erupt (derivationally related)
• (suomi) purkautuminen (synonyymi)

irruption

• (englanti) irrupt (derivationally related)
• (suomi) valloilleen pääsy (synonyymi)

outbreak

• (suomi) purkaus (synonyymi)

• (suomi) puhkeaminen (synonyymi)