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

An increase in gas emissions confirms that new magma has entered the Earth’s crust beneath the volcano, indicating that an eruption is likely in the next weeks or months, according to the observatory. —Julia Jacobo, ABC News, 13 Mar. 2025

Fresh magma has intruded into the Earth’s crust underneath Alaska’s Mount Spurr, 75 miles west of Anchorage, increasing the likelihood of an eruption within the near future, government officials said Wednesday afternoon. —Marc Ramirez, USA TODAY, 12 Mar. 2025

Off the coast of Japan, thousands of feet below the surface, the seafloor explodes with heat. Cracks and vents in the rocky sediment allow boiling seawater heated by subterranean magma to shoot back up into the sea, reaching temperatures of more than 700 degrees Fahrenheit. —Irene Wright, Miami Herald, 10 Feb. 2025

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

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