Definition of magma

• n. - Any crude mixture of mineral or organic matters in the state of a thin paste.
• n. - A thick residuum obtained from certain substances after the fluid parts are expressed from them; the grounds which remain after treating a substance with any menstruum, as water or alcohol.
• n. - A salve or confection of thick consistency.
• n. - The molten matter within the earth, the source of the material of lava flows, dikes of eruptive rocks, etc.
• n. - The glassy base of an eruptive rock.
• n. - The amorphous or homogenous matrix or ground mass, as distinguished from well-defined crystals; as, the magma of porphyry.