We Have a Word For It ... And Here's Why

Matrix • Fingernails and toenails grow from a source called the "nail matrix" and grow out over the "nail bed." The nail itself is called the "nail plate." As well as providing the name for a cool, if violent movie series, matrix has a surprising history. The movie The Matrix series takes its name from computing, where a matrix is an interconnected complex of related elements. But matrix was originally a Latin word meaning "uterus" or "womb," and appeared in that sense in English in 1526. Think matrix, mater, mother. The nail matrix is in this sense the place of origin of the nail, the place where it is born. In The Matrix movies those evil computers have set up artificial wombs where they can breed more humans; lending the name a nice circularity.

Carnal Knowledge by Charles Hodgson