/ Dictionary / Index T thionyl chloride: Meaning and Definition of Find definitions for: thi'onyl chlo'ride Pronunciation: [key] — Chem. Chem. a clear, pale yellow or red, fuming, corrosive liquid, SOCl, used chiefly in organic synthesis. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. thionyl thiopental sodium Related Content Daily Word Quiz: reiterate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language