/ Dictionary / Index P phase diagram: Meaning and Definition of Find definitions for: phase' di"agram Pronunciation: [key] — Chem. Chem. a graph, usually using temperature, pressure, and composition as coordinates, indicating the regions of stability of the various phases of a system. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. phased array phasedown 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