/ Dictionary / Index P propylene glycol: Meaning and Definition of Find definitions for: pro'pylene gly'col Pronunciation: [key] — Chem. Chem. a colorless, viscous, hygroscopic liquid, CHO, used chiefly as a lubricant, as an antifreeze, as a heat transfer fluid, and as a solvent for fats, oils, waxes, and resins. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. propylene propylene group Related Content Daily Word Quiz: careening Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language