matrix

Etymology

From Middle English matris, matrice, matrix, from Old French matrice (“pregnant animal”), or from Latin mātrīx (“dam, womb”), from māter (“mother”). Slang usage coined with the 1999 sci-fi action film The Matrix.

noun

1. A table of data.
2. The cavity or mold in which anything is formed.
3. (biology) The material or tissue in which more specialized structures are embedded.
4. (biology) An extracellular matrix, the material or tissue between the cells of animals or plants.
5. (biology) Part of the mitochondrion.
6. (biology) The medium in which bacteria are cultured.
7. (slang, figurative) a term describing a controlled environment or situation in which people act or behave in ways that conform to roles pre-determined by a powerful person(s) who decides how the world is supposed to function (as if the world is but virtual reality and people but brains in a vat).
   The Matrix has attacked me
8. (mathematics) A rectangular arrangement of numbers or terms having various uses such as transforming coordinates in geometry, solving systems of linear equations in linear algebra and representing graphs in graph theory.
   Theorem (7.5.2) then says that every positive semidefinite matrix is a convex combination of matrices that lie on extreme rays. 1987, [1985], Roger A. Horn, Charles R. Johnson, Matrix Analysis, Paperback edition, Cambridge University Press, published 1990, page 464
   Check that the 𝒜(𝒟)² in the example is itself the adjacency matrix of the indicated digraph: 2003, Robert A. Liebler, Basic Matrix Algebra with Algorithms and Applications, CRC Press (Chapman & Hall/CRC), page 64
   2007, Gerhard Kloos, Matrix Methods for Optical Layout, SPIE Press, page 25, The matrix describing the reflection at a plane mirror can be obtained by taking the matrix for reflection at a spherical reflector and letting the radius of the spherical mirror tend to infinity.
9. (computing) A two-dimensional array.
10. (electronics) A grid-like arrangement of electronic components, especially one intended for information coding, decoding or storage.
    Any type of core or diode matrix used to derive the decoding of these codes would amount to a rather large volume of terminals for just the 17,500 terminals alone. 1949, Proceedings of the Association of American Railroads
    The transistor matrix in the encoder supplies the sequential gates. 1959, John Millar Carroll, Modern Transistor Circuits
    A transistor-diode matrix is composed of vertical and horizontal wires with a transistor at each intersection. 1962, Burroughs Corporation, Digital Computer Principles
    Robot controllers range in complexity from simple stepping switches through pneumatic logic sequencers, diode matrix boards, electronic sequencers, and microprocessors to minicomputers. 1987, David Ardayfio, Fundamentals of Robotics
    Diode matrix is the most fundamental of all ROM structure. 2002, B. Somantathan Nair, Digital Electronics and Logic Design
11. (geology) A geological matrix.
12. (archaeology and paleontology) The sediment surrounding and including the artifacts, features, and other materials at a site.
13. (analytical chemistry) The environment from which a given sample is taken.
14. (printing, historical) In hot metal typesetting, a mold for casting a letter.
15. (printing, historical) In printmaking, the plate or block used, with ink, to hold the image that makes up the print.
16. (dyeing) The five simple colours (black, white, blue, red, and yellow) from which all the others are formed.
17. (material science) A binding agent of composite materials, e.g. resin in fibreglass.
18. (now rare) The womb.