magma

noun

mag·​ma ˈmag-mə How to pronounce magma (audio)
1
archaic : dregs, sediment
2
: a thin pasty suspension (as of a precipitate in water)
3
: molten rock material within the earth from which igneous rock results by cooling
magmatic adjective

Examples of magma in a Sentence

Recent Examples on the Web
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So Hendon collaborated with volcanologists Josef Dufek and Joshua Méndez Harper, who were regulars at the same local coffee house and had noted striking similarities between the science of coffee and plumes of volcanic ash, magma, and water. ArsTechnica, 28 Apr. 2026 The magma had significant upward momentum. Robin George Andrews, Scientific American, 23 Apr. 2026 The presence of anorthosite on the moon suggested that the entire orb was once a magma ocean, or completely molten. Jackie Wattles, CNN Money, 6 Apr. 2026 Here magma, thin crust, and high-heat flow allow for easy access to underground steam or hot water. Encyclopedia Britannica, 2 Apr. 2026 See All Example Sentences for magma

Word History

Etymology

Middle English, from Latin magmat-, magma, from Greek, thick unguent, from massein to knead — more at mingle

First Known Use

15th century, in the meaning defined at sense 1

Time Traveler
The first known use of magma was in the 15th century

Browse Nearby Words

Cite this Entry

“Magma.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/magma. Accessed 1 May. 2026.

Kids Definition

magma

noun
mag·​ma ˈmag-mə How to pronounce magma (audio)
: molten rock material within the earth
magmatic adjective

Medical Definition

magma

noun
mag·​ma ˈmag-mə How to pronounce magma (audio)
1
: a crude mixture of mineral or organic matter in the state of a thin paste
2
: a suspension of a large amount of precipitated material (as in milk of magnesia) in a small volume of a watery vehicle

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