erupt
Definitions
To break out or burst forth suddenly, as with lava, steam, or water from a volcano or geyser.
To become active or violent suddenly, such as a conflict, disease, or emotional outburst.
To appear suddenly on the skin, as with a rash or pimples.
Examples
The volcano began to erupt, sending plumes of ash high into the atmosphere.
Tensions between the two rival groups threatened to erupt into open conflict at any moment.
A sudden rash of spots started to erupt across her skin after she tried the new soap.