Geyser comes from Icelandic Geysir, the name of a particular hot spring. The name is related to a verb for rushing forth. English turned that local proper name into a general label for similar springs elsewhere.
geyser
A spring that periodically erupts with hot water.
Geyser came from Icelandic.
How geyser reached English
oldest firstSimplified path. The puzzle showed the main steps; the full route is being checked.
Icelandic
geysa
‘To rush forth’
Icelandic
Geysir
‘The named spring’
into English
English
geyser
‘An erupting hot spring’
The story of geyser
Related
A place or feature’s own name can become the name of an entire category.