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
mag-ˈma-tik How to pronounce magma (audio)
adjective

Examples of magma in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
In the soft light of dawn, an Ohio tourist studied the interpretive sign at the summit of Cadillac Mountain in Acadia National Park, reading about how magma formed the ground under her feet. — ABC News, 22 Oct. 2026 Kicking off the trailer is a pan over the ever-flowing magma region of Mordor. — Destiny Jackson, Deadline, 21 Oct. 2026 The other bit of information from the chemistry of the eruption is from magnesium oxide, which provides an indication of the temperature of the magma. — John Timmer, ArsTechnica, 9 Oct. 2026 Volcanologists could use the technology to map internal magma chambers and lava tubes to help predict eruptions. — Mrigakshi Dixit, Interesting Engineering, 2 Oct. 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

maglev
magma
magma chamber
See all Nearby Words

Cite this Entry

“Magma.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/magma. Accessed 30 Oct. 2026.

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Kids Definition

magma

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

More from Merriam-Webster on magma

Britannica.com: Encyclopedia article about magma

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