magma (n.)

mid-15c., "dregs, any crude mixture of organic matter," from Latin magma "dregs of an ointment," from Greek magma "thick unguent, ointment," from root of massein "to knead, mold," from PIE root *mag- "to knead, fashion, fit." Geological meaning "molten or semi-molten rock" is by 1859. Related: Magmatic.