ig·​ne·​ous ˈig-nē-əs How to pronounce igneous (audio)
: formed by solidification of magma
igneous rock
: relating to, resulting from, or suggestive of the intrusion or extrusion of magma or volcanic activity
: of, relating to, or resembling fire : fiery

Example Sentences

Recent Examples on the Web Heavy REEs—those with high atomic numbers, including dysprosium, yttrium, and terbium—are most commonly extracted from masses of clay formed through eons of weathering of igneous rocks such as granite. Bydennis Normile, science.org, 1 Nov. 2022 These igneous rocks contain radioactive elements such as uranium. Byeric Hand, science.org, 20 Sep. 2022 The rover previously explored Jezero Crater's floor, finding igneous rocks. Wyatte Grantham-philips, USA TODAY, 16 Sep. 2022 The rover previously found igneous rocks, likely formed deep underground through volcanic processes, on the crater floor. Denise Chow, NBC News, 15 Sep. 2022 The rover investigated the crater floor and found evidence of igneous, or volcanic, rock. Ashley Strickland, CNN, 15 Sep. 2022 This is a bonus because the igneous rocks discovered—specifically the samples from formations called Máaz and Séítah—likely predate the river delta. Jamie Carter, Forbes, 25 Aug. 2022 During its first scientific campaign, the rover explored the crater’s floor, finding igneous rock. Julia Musto, Fox News, 16 Sep. 2022 In an early surprise, the rover found igneous rock well away from the rim of Jezero Crater where scientists had expected to find sedimentary lakebed layers. William Harwood, CBS News, 15 Sep. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'igneous.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


Latin igneus, from ignis fire; akin to Sanskrit agni fire

First Known Use

1664, in the meaning defined at sense 2

Time Traveler
The first known use of igneous was in 1664

Dictionary Entries Near igneous

Cite this Entry

“Igneous.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/igneous. Accessed 1 Dec. 2022.

Kids Definition



ig·​ne·​ous ˈig-nē-əs How to pronounce igneous (audio)
: formed by hardening of melted earth
igneous rock
compare metamorphic, sedimentary sense 2

More from Merriam-Webster on igneous

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