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

In a study published March 2026 in the journal Nature Communications, our team of physicists and geoscientists investigated ilmenite, a mineral composed of iron, titanium and oxygen, in a Moon rock crystallized from an ancient lunar magma. —Emily First, The Conversation, 27 Mar. 2026

When magma breaches the surface of the Earth, it’s usually called lava. —Quanta Magazine, 27 Mar. 2026

Whether modern plate tectonics arose directly from the hellish magma ocean that once covered early Earth or whether intermediate stages, such as plates that moved intermittently or one single, unbroken lid, were at play is also unclear, the study authors noted. —Katie Hunt, CNN Money, 25 Mar. 2026

Unlike the near side of the moon, which is characterized by large basaltic planes called maria that formed when magma welled up in impact craters, the far side is mostly an ancient crust of feldspar-rich rock called anorthosite. —Jay Bennett, Wired News, 24 Mar. 2026

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