Matrix Ma"trix, n.; pl. Matrices. [L., fr. mater mother. See Mother, and cf. Matrice.] 1. (Anat.) The womb. All that openeth the matrix is mine. --Ex. xxxiv. 19. 2. Hence, that which gives form or origin to anything; as: (a) (Mech.) The cavity in which anything is formed, and which gives it shape; a die; a mold, as for the face of a type. (b) (Min.) The earthy or stony substance in which metallic ores or crystallized minerals are found; the gangue. (c) pl. (Dyeing) The five simple colors, black, white, blue, red, and yellow, of which all the rest are composed. 3. (Biol.) The lifeless portion of tissue, either animal or vegetable, situated between the cells; the intercellular substance. 4. (Math.) A rectangular arrangement of symbols in rows and columns. The symbols may express quantities or operations.