Geyser
late 18th century: from Icelandic Geysir, the name of a particular spring in Iceland; related to geysa ‘to gush’.
wiktionary
From the name of a particular Icelandic geyser which is mentioned as early as the 1760s in The Annual Register, as “Geyser, a wonderful spring in the valley of Haukadal”. [1] From Geysir(“Gusher”), the Icelandic name of the hot spring in Iceland (see Wikipedia), from the verb geysa(“to gush”), from Old Norse geysa(“to gush”). Doublet of gusher.
etymonline
geyser (n.)
1780, extended from Icelandic Geysir, name of a specific hot spring in the valley of Haukadal, literally "the gusher," from Old Norse geysa "to gush," from Proto-Germanic *gausjan, suffixed form of PIE *gheus-, extended form of the root *gheu- "to pour." Taken by foreign writers as the generic name for spouting hot springs, for which the native Icelandic words are hverr "a cauldron," laug "a hot bath."
