1. A natural hot spring that intermittently ejects a column of water and steam into the air.
2. (gēzər) Chiefly British A gas-operated hot-water heater.
[After Icelandic Geysir, name of a hot spring of southwest Iceland, from geysa, to gush, from Old Norse; see gheu- in the Appendix of Indo-European roots.]
(click for a larger image)geyser
Water contained in porous rock seeps into an opening. Heated by magma below, it escapes under pressure to the earth's surface.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2017 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.
American Heritage Dictionary Products
The American Heritage Dictionary, 5th Edition
The American Heritage Dictionary of Idioms
The American Heritage Roget's Thesaurus
Curious George's Dictionary
The American Heritage Children's Dictionary
The American Heritage Dictionary of Indo-European Roots
The American Heritage Student Grammar Dictionary
The American Heritage Desk Dictionary + Thesaurus
The American Heritage Science Dictionary
The American Heritage Dictionary of Business Terms
The American Heritage Student Dictionary
The American Heritage Essential Student Thesaurus