geyser

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

2. (by extension) A momentary vertical jet or fountain of fluid driven upwards by a violent force.Examples: "Sporting a few war wounds from Japanese destroyer gunfire, The Sullivans had already launched one spread of torpedoes at the Japanese destroyers that were now littering the ocean floor, or, occasionally, making their own retreat, but she still had one left, so a five-torpedo spread was duly sent at near-point-blank range into the listing and burning remains of Yamato, and, shortly thereafter, four large geysers of water were the reward."broadly

3. (British, archaic) An instantaneous, and often dangerous, hot water heater.Examples: "Where a Geyser or hot-water heater is used it is a good and wise precaution to see that the bath-room, &c., when it is used is well ventilated."; "Water was heated either on the gas stove, or on a wall mounted gas-fired "geyser" heater."; "It was here I saw a geyser gas water heater in a bathroom for the first time. (I was afraid of it)."Britisharchaic

4. (South Africa, South Asia) A domestic water boiler.South-AfricaSouth-Asia