Definition of "Matrix" :

noun: mold used in the production of phonograph records, type, or other relief surface

noun: the formative tissue at the base of a nail

noun: the body substance in which tissue cells are embedded

noun: (mathematics) a rectangular array of quantities or expressions set out by rows and columns; treated as a single element and manipulated according to rules

noun: an enclosure within which something originates or develops (from the Latin for womb)

noun: (geology) a mass of fine-grained rock in which fossils, crystals, or gems are embedded