magma
UK: ˈmaɡmə | US: ˈmæɡmə
n. hot fluid or semifluid material below or within the earth's crust, from which igneous rock is formed by cooling.
The word "magma" originates from Greek mágma (μᾶγμα), meaning "thick unguent" or "kneaded substance," derived from the verb mássō (μάσσω, "to knead"). This reflects the viscous, malleable nature of molten rock beneath the Earth's surface. The term was adopted into Latin as magma (ointment, dregs) and later specialized in geology (mid-19th century) to describe molten rock. The morpheme mag- preserves the ancient idea of plasticity, while -ma functions as a noun-forming suffix.
Volcanic eruptions occur when magma rises to the surface.
Geologists study magma composition to predict volcanic activity.
The magma chamber beneath Yellowstone is vast and dynamic.
Basalt forms from rapidly cooled magma.
Magma viscosity depends on its silica content.