1. （火山）喷发，爆发
When a volcano erupts, it throws out a lot of hot, melted rock called lava, as well as ash and steam.
1. become active and spew forth lava and rocks
e.g. Vesuvius erupts once in a while
Synonym: belchextravasate
2. erupt or intensify suddenly
e.g. Unrest erupted in the country
Tempers flared at the meeting
The crowd irrupted into a burst of patriotism
Synonym: irruptflare upflarebreak openburst out
3. become raw or open
e.g. He broke out in hives
My skin breaks out when I eat strawberries
Such boils tend to recrudesce
Synonym: recrudescebreak out
4. start abruptly
e.g. After 1989, peace broke out in the former East Bloc
Synonym: break out
5. appear on the skin
e.g. A rash erupted on her arms after she had touched the exotic plant
6. break out
e.g. The tooth erupted and had to be extracted
Synonym: come outbreak throughpush through
7. force out or release suddenly and often violently something pent up
e.g. break into tears
erupt in anger
8. start to burn or burst into flames
e.g. Marsh gases ignited suddenly
The oily rags combusted spontaneously