The definition of a geyser is a natural hot spring that boils and lets out a large burst of water and steam from time to time.(noun)
An example of a geyser is Old Faithful in Yellowstone National Park.
See geyser in Webster's New World College Dictionary
Origin: Ice Geysir, name of a certain hot spring in Iceland, lit., gusher < ON gjosa, to gush
See geyser in American Heritage Dictionary 4
Origin: After Icelandic Geysir, name of a hot spring of southwest Iceland
Origin: , from geysa, to gush
Origin: , from Old Norse; see gheu- in Indo-European roots.
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