[ jee-ohd ]
/ ˈdʒi oʊd /
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a hollow concretionary or nodular stone often lined with crystals.
the hollow or cavity of this.
any similar formation.



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Origin of geode

1670–80; <French géode<Latin geōdēs<Greek geṓdēs earthlike. See geo-, -ode1
ge·od·ic [jee-od-ik], /dʒiˈɒd ɪk/, ge·od·al [jee-ohd-l], /dʒiˈoʊd l/, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

British Dictionary definitions for geode

/ (ˈdʒiːəʊd) /


a cavity, usually lined with crystals, within a rock mass or nodule
geodic (dʒɪˈɒdɪk), adjective
C17: from Latin geōdēs a precious stone, from Greek: earthlike; see geo-, -ode 1
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for geode

[ jēōd′ ]


A cystlike space with or without an epithelial lining, usually observed in subarticular bone in arthritic disorders.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for geode

[ jēōd′ ]

A small, hollow, usually rounded rock lined on the inside with inward-pointing crystals. Geodes form when mineral-rich water entering a cavity in a rock undergoes a sudden change in pressure or temperature, causing crystals to form from the solution and line the cavity's walls.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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