/ Dictionary / Index O osmotic pressure: Meaning and Definition of Find definitions for: osmot'ic pres'sure Pronunciation: [key] — Physical Chem. Physical Chem. the force that a dissolved substance exerts on a semipermeable membrane, through which it cannot penetrate, when separated by it from pure solvent. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. osmosis osmund Related Content Daily Word Quiz: frugal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language