n (mathematics) a rectangular array of quantities or expressions set out by rows and columns; treated as a single element and manipulated according to rules n (geology) amass of fine-grained rock in which fossils, crystals, or gems are embedded n an enclosure within which something originates or develops (from the Latin for womb) n the body substance in which tissue cells are embedded n the formative tissue at the base of a nail n mold used in the production of phonograph records, type, or other relief surface