\Gey"ser\, n. [Icel. geysir, fr. geysa to rush furiously,
fr. gj[=o]sa to gush. Cf. {Gush}.]
A boiling spring which throws forth at frequent intervals
jets of water, mud, etc., driven up by the expansive power of
steam.
Note: Geysers were first known in Iceland, and later in New
      Zealand. In the Yellowstone region in the United States
      they are numerous, and some of them very powerful,
      throwing jets of boiling water and steam to a height of
      200 feet. They are grouped in several areas called
      geyser basins. The mineral matter, or geyserite, with
      which geyser water is charged, forms geyser cones about
      the orifice, often of great size and beauty.