/ Dictionary / Index P positive definite: Meaning and Definition of Find definitions for: pos'itive def'inite Pronunciation: [key] — Math. Math. (of a quadratic form) positive for all real values of the variables, where the values are not all zero. (of a matrix) displaying the coefficients of a positive definite quadratic form. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. positive crankcase ventilation positive electricity Related Content Daily Word Quiz: cygnet Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language