magma

noun

mag·​ma ˈmag-mə 

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 

adjective

Examples of magma in a Sentence

Recent Examples on the Web

Puy de Dôme formed about 11,000 years ago when a fist of magma punched up into the rolling hills of central France. —Carl Zimmer, Smithsonian Magazine, 25 Feb. 2025

Authorities had previously warned of volcanic activity as magma accumulated beneath the Reykjanes peninsula, some 20 miles southwest of the capital, Reykjavik, where the most recent eruption ended only on Sept. 6. —Reuters, NBC News, 21 Nov. 2024

So many people got out their garden hoses after that eruption covered cars and yards with fine grains of magma that there was record water demand, Haney said. —Elizabeth Weise, USA TODAY, 17 Feb. 2025

The researchers noted multiple reservoirs of magma sitting asymmetrically beneath the Earth’s crust. —Paul Smaglik, Discover Magazine, 28 Jan. 2025

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

Kids Definition

magma

noun

mag·​ma ˈmag-mə 

: molten rock material within the earth

magmatic

mag-ˈmat-ik 

adjective

Medical Definition

magma

noun

mag·​ma ˈmag-mə 

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