Meaning of positive definite

pos'itive def'inite

Pronunciation: [key]
— Math. Math.
  1. (of a quadratic form) positive for all real values of the variables, where the values are not all zero.
  2. (of a matrix) displaying the coefficients of a positive definite quadratic form.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.