From Longman Dictionary of Contemporary Englishmagmamag‧ma /ˈmæɡmə/ noun [uncountable] technicalHEG hot melted rock below the surface of the Earth
Examples from the Corpus
magma• Pastures of fresh magma flows known as pillow lavas and the rubble of frequent earthquakes line the floor of this stone trough.• Hot magma bubbled up through the older parts of Laurentia west of Hudson Bay, signaling the start of continental rifting.• Igneous intrusions injected as a mobile magma may show sharp contacts with surrounding, or country, rocks.• Some attributed each crater to a bursting giant bubble of gases escaping from a vast ocean of magma.• Eruptions can occur through either fissures or vents, again depending on magma type.• The south-southeast-trending increase is most probably the result of a shallow magma intrusion.• Different minerals in the magma create different structures.• A single deep connection to the magma supply maintains the heat input by convection.Origin magma (1400-1500) Latin Greek, from massein “to press and mix together” 