Matrix noun 1 : something within or from which something else originates, develops, or takes form an atmosphere of understanding and friendliness that is the matrix of peace 2 a : a mold from which a relief (see RELIEF entry 1 sense 6) surface (such as a piece of type) is made b : DIE sense 3a(1) c : an engraved or inscribed die (see DIE entry 2 sense 3) or stamp d : an electroformed impression of a phonograph record used for mass-producing duplicates of the original 3 a : the natural material (such as soil or rock) in which something (such as a fossil or crystal) is embedded b : material in which something is enclosed or embedded (as for protection or study) 4 a : the extracellular substance in which tissue cells (as of connective tissue) are embedded b : the thickened epithelium at the base of a fingernail or toenail from which new nail substance develops 5 a : a rectangular array (see ARRAY entry 2 sense 5) of mathematical elements (such as the coefficients (see COEFFICIENT sense 1) of simultaneous (see SIMULTANEOUS sense 2) linear equations) that can be combined to form sums and products with similar arrays having an appropriate number of rows and columns b : something resembling a mathematical matrix especially in rectangular arrangement of elements into rows and columns c : an array of circuit elements (such as diodes and transistors) for performing a specific function 6 : a main (see MAIN entry 2 sense 5) clause that contains a subordinate (see SUBORDINATE entry 1) clause ←Click the Matrix Button on the left