Emily Dickinson Lexicon

MA'TRICE, or MATRIX, n. [L. matrix, from mater, mother.]

1. The womb; the cavity in which the fetus of an animal is formed and nourished till its birth. Encyc.
2. A mold; the cavity in which any thing is formed, and which gives it shape; as, the matrix of a type.
3. The place or substance in which any thing is formed or produced; as, the matrix of metals; gang.
4. In dyeing, the five simple colors, black, white, blue, red and yellow, of which all the rest are composed. Encyc.