geode

[ jee-ohd ]

noun

a hollow concretionary or nodular stone often lined with crystals.
the hollow or cavity of this.

any similar formation.

Origin of geode

1670–80; <French géode<Latin geōdēs<Greek geṓdēs earthlike. See geo-, -ode¹

Other words from geode

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. 2023

How to use geode in a sentence

These geodes, on breaking, often present a mammillary surface.
Summary Narrative of an Exploratory Expedition to the Sources of the Mississippi River, in 1820 | Henry Rowe Schoolcraft
I have since learned that such stones are found at many points, and that they are called geodes.
Death Valley in '49 | William Lewis Manly
Many sorts there are of this ratling Stone, beside the Geodes, containing a softer substance in it.
The Works of Sir Thomas Browne (Volume 1 of 3) | Thomas Browne
This was a strange place, and in our search we found geodes, petrified snakes, and short sections of fish.
The Sheep Eaters | William Alonzo Allen
Besides quartz crystals, others of calcareous spar are sometimes found in the cavities of geodes.
The Chautauquan, Vol. III, March 1883 | The Chautauquan Literary and Scientific Circle

British Dictionary definitions for geode

geode

/ (ˈdʒiːəʊd) /

noun

a cavity, usually lined with crystals, within a rock mass or nodule

Origin of geode

C17: from Latin geōdēs a precious stone, from Greek: earthlike; see geo-, -ode 1

Derived forms of geode

geodic (dʒɪˈɒdɪk), adjective

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

Scientific definitions for geode

geode

[ jē′ōd′ ]

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.

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