/ Dictionary / Index P partial pressure: Meaning and Definition of Find definitions for: par'tial pres'sure Pronunciation: [key] — Physics, Chem. Physics,Chem. the pressure that a gas in a mixture of gases would exert if it occupied the same volume as the mixture at the same temperature. Cf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. partial ordering partial score Related Content Daily Word Quiz: deleterious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language