What is the meaning of Geyser?

A boiling natural spring which throws forth jets of water, mud, etc., at frequent intervals, driven upwards by the expansive power of steam.

A momentary vertical jet or fountain of fluid driven upwards by a violent force.

An instantaneous, and often dangerous, hot water heater.

A domestic water boiler.

To (cause to) rush or burst upward like water from a geyser.

geyser

Alternative spelling of geiser (geyser)

Source: wiktionary.org