magma

MAG-muh /ˈmæɡ.mə/
nounB2TOEFLIELTSSAT
scientific

Hot fluid or semi-fluid material below or within the Earth's crust, from which lava and other igneous rock is formed by cooling.

Magma is underground; once it erupts onto the Earth's surface, it is called lava.

The story behind the word. The word stems from Ancient Greek 'magma', meaning a kneaded paste or thick unguent, from 'massein' (to knead). Early naturalists used it to describe the thick, paste-like consistency of underground molten rock.

Word relationships

  • molten rock: Molten rock is an everyday descriptive phrase, whereas magma is the precise geological term for subterranean liquid rock.
  • lava: Lava is molten rock above ground, whereas magma is molten rock below ground.
  • solid rock: Solid rock is rigid and cool, whereas magma is fluid and intensely hot.

Commonly confused with

  • lava: Magma is inside the Earth's surface; lava is magma that has breached the surface.

Word family

  • magmatic (adjective): Pertaining to or derived from magma

Collocations

  • magma chamber
  • molten magma
  • magma plume
  • magma flow

Example sentences

  • "Liquid magma gathered in a vast chamber deep beneath the volcano prior to the explosive eruption." Volcanology
  • "As magma cools slowly under the ground, large visible mineral crystals form within the resulting rock." Geological field report

Memory hook

MAGMA stays in Earth's STOMACH; LAVA LEAVES the surface. Subterranean molten paste.

When not to use

Do not call liquid rock on the surface magma; that is lava.

Fun facts

  • Magma temperatures range between 700°C and 1300°C (1300°F to 2400°F).

Related words

igneous, crystallize

LangBlitz
Take your vocabulary further with LangBlitz

Our English vocabulary app: FSRS spaced repetition, 5,000+ curated words across 119 topic groups, CEFR A1 to C2. Explore your mastery with the beautiful Vocabulary World feature.