/ Dictionary / Index I ideal gas law: Meaning and Definition of Find definitions for: ide'al gas' law" Pronunciation: [key] — Physics. Physics. the law that the product of the pressure and the volume of one gram molecule of an ideal gas is equal to the product of the absolute temperature of the gas and the universal gas constant. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ideal gas idealism Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language