(mathematics) a rectangular array of quantities or expressions set out by rows and columns; treated as a single element and manipulated according to rules
"The professor asked us to multiply the two matrices to find the resulting transformation."
(geology) a mass of fine-grained rock in which fossils, crystals, or gems are embedded
"The geologist carefully chipped away at the limestone matrix to reveal the rare fossilized ammonite hidden within."
an enclosure within which something originates or develops (from the Latin for womb)
"The quiet suburb served as a matrix from which several successful tech startups emerged over the last decade."
the body substance in which tissue cells are embedded
"The pathologist examined the hardening of the connective tissue matrix to determine if fibrosis was affecting the organ's function."
the formative tissue at the base of a nail
"After cutting too much off my hangnail, I accidentally nicked the matrix and now my new growth is growing in crooked."
mold used in the production of phonograph records, type, or other relief surface
"The old audio engineer spent hours cleaning the master matrix to ensure the new vinyl pressing would have crisp sound."
The womb.
"The ancient myth describes the universe as a giant matrix from which all life emerges."
In plain English: A matrix is a rectangular grid of numbers arranged in rows and columns used to organize data for math calculations.
"The software developer created a complex matrix to organize all the data."
Usage: In everyday usage, matrix refers to an environment or medium in which something develops, such as a social system or a mold for casting objects. Although it historically means womb, modern speakers almost always use it to describe the surrounding structure that shapes growth rather than biological reproduction.
A simulated reality created by sentient machines to subdue humans.
"After waking up from his long cryosleep, Neo realized he had been living inside a machine-generated simulation designed to control humanity."
The word matrix comes from the Latin mātrīx, meaning "womb" or "dam," and entered English via Old French to describe a pregnant animal before broadening its sense in modern usage. Its connection to slang is distinct, as the 1999 film The Matrix coined the specific pop-culture definition of a simulated reality.