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

And because our planet back then was a seething ball of magma, the lunar nearside should have been baked like crème brûlée, with the nearside turning molten and bubbly. —Robin George Andrews, Scientific American, 7 Apr. 2026

The presence of anorthosite on the moon suggested that the entire orb was once a magma ocean, or completely molten. —Jackie Wattles, CNN Money, 6 Apr. 2026

Here magma, thin crust, and high-heat flow allow for easy access to underground steam or hot water. —Encyclopedia Britannica, 2 Apr. 2026

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

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