/ Dictionary / Index G Graham's law of diffusion: Meaning and Definition of Find definitions for: Gra'ham's law' of diffu'sion Pronunciation: [key] — Physical Chem. Physical Chem. the principle that at a given temperature and pressure the rate of diffusion of a gas is inversely proportional to the square root of its density. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Graham Land graham wafer Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language