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

Earth today is a jigsaw of giant chunks of crust that travel across the planet, smashing together like huge bumper cars, pushing up mountain ranges and melting back into magma along their edges. —Marissa Grunes, Scientific American, 19 Mar. 2026

Ultraviolet light from its host star triggers the creation of sulfur dioxide in the upper atmosphere, and a massive sub-surface magma ocean acts as a buffer, storing and releasing volatile gases over billions of years. —Mrigakshi Dixit, Interesting Engineering, 16 Mar. 2026

It is covered in oceans made of magma and has an atmosphere made of sulfur, according to a paper published Monday in Nature Astronomy. —Julia Jacobo, ABC News, 16 Mar. 2026

The United States Geological Survey said fallout had created hazardous conditions in downwind areas, with one resident reporting more than an inch of tephra — a mix of magma, rock and volcanic glass — on the roads of a golf course subdivision. —Marc Ramirez, USA Today, 10 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