eruption

noun

1. the sudden occurrence of a violent discharge of steam and volcanic material
2. symptom consisting of a breaking out and becoming visible
3. (of volcanoes) pouring out fumes or lava (or a deposit so formed)
4. a sudden violent spontaneous occurrence (usually of some undesirable condition)"the outbreak of hostilities"
5. a sudden very loud noise
6. the emergence of a tooth as it breaks through the gum