e·rup·tion 
(ĭ-rŭpshən)
(ĭ-rŭpshən)n.
1.
a. The act or process of erupting.
b. An instance of erupting.
2. A sudden, often violent outburst.
3.
a. An appearance of a rash or blemish on the skin.
b. Such a rash or blemish.
4. The emergence of a tooth through the gums.
eruptionWhite Dome geyser Lower Geyser Basin Yellowstone National Park, Wyoming