ETYM Icel. geysir, from geysa to rush furiously, from gjôsa to gush. Related to Gush.
A spring that discharges hot water and steam.
Natural spring that intermittently discharges an explosive column of steam and hot water into the air due to the buildup of steam in underground chambers. One of the most remarkable geysers is Old Faithful, in Yellowstone National Park, Wyoming, US. Geysers also occur in New Zealand and Iceland.