/ Dictionary / Index M mixing ratio: Meaning and Definition of Find definitions for: mix'ing ra"tio Pronunciation: [key] the ratio of the mass of water vapor in the air to the mass of the dry air, a measure of atmospheric humidity. Cf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mixing faucet mixing valve Related Content Daily Word Quiz: soporific Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language