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

Mystery of the floating island Volcanic islands, like the famed Hawaiian chain, are typically buoyed by hot, active magma plumes pushing up the Earth’s crust. —Mrigakshi Dixit, Interesting Engineering, 16 Dec. 2025

Here, the African and Arabian tectonic plates are slowly pulling apart, thinning Earth's crust and allowing magma to rise close to the surface. —Kenna Hughes-Castleberry, Space.com, 16 Dec. 2025

Typically, volcanic islands are buoyed by magma plumes, which push the crust of the Earth up. —Julia Jacobo, ABC News, 15 Dec. 2025

Observations suggest the exoplanet has a global magma ocean and that it is surrounded by a thick layer of gas. —Kerry Breen, CBS News, 12 Dec. 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