1.start abruptly;
After 1989, peace broke out in the former East Bloc
2.erupt or intensify suddenly;
Unrest erupted in the country
3.start to burn or burst into flames;
Marsh gases ignited suddenly
4.as of teeth, for example;
The tooth erupted and had to be extracted
5.become active and spew forth lava and rocks;
Vesuvius erupts once in a while
6.force out or release suddenly and often violently something pent up;
break into tears
7.appear on the skin;
A rash erupted on her arms after she had touched the exotic plant
8.become raw or open;
He broke out in hives