ETYM Latin, from mater mother. Related to Mother, Matrice.
In biology, usually refers to the extracellular matrix.1. A rectangular array of elements set out by rows and columns.
2. An enclosure within which something originates or develops (from the Latin for womb).
3. The body substance in which tissue cells are embedded; SYN. intercellular substance, ground substance.
4. The formative tissue at the base of a nail.
5. Used in the production of phonograph records, type, or other relief surface.
Womb; mold for casting; cement.

An arrangement of rows and columns used for organizing related items, such as numbers, dots, spreadsheet cells, or circuit elements. Matrices are used in mathematics for manipulating rectangular sets of numbers. In computing and computer applications, matrices are used for the similar purpose of arranging sets of data in table form, as in spreadsheets and lookup tables. In hardware, matrices of dots are used in creating characters on the screen as well as in print (as by dot-matrix printers). In electronics, matrices of diodes or transistors are used to create networks of logic circuits for such purposes as encoding, decoding, or converting information. See also grid.

In mathematics, a square (n x n) or rectangular (m x n) array of elements (numbers or algebraic variables). They are a means of condensing information about mathematical systems and can be used for, among other things, solving simultaneous linear equations (see simultaneous equations and transformation).
Much early matrix theory was developed by the British mathematician Arthur Cayley, although the term was coined by his contemporary James Sylvester (1814–1897).