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

Together, these methods point to a hydrothermal system rather than surging magma as the cause of Uturuncu’s activity, and provide a snapshot of the interplay between magma, rock and fluid under volcanoes. —Mindy Weisberger, CNN Money, 5 May 2025

When magma is formed in the mantle source, thorium, like water, remains in the melt rather than producing crystalline minerals. —Keith Cooper, Space.com, 9 Apr. 2025

In those places—generally volcanic hot spots where magma flows at shallow depths in the Earth’s crust and underground water reservoirs—geothermal energy can be a substantial source of power. —Alexander C. Kaufman, The Atlantic, 4 Apr. 2025

While magma has yet to reach the surface, authorities warn that an eruption could happen with little notice. —Josh Hammer, MSNBC Newsweek, 1 Apr. 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