/ Dictionary / Index T thio: Meaning and Definition of Find definitions for: thi•o Pronunciation: (thī'ō), [key] — adj. Chem. containing sulfur, esp. in place of oxygen. thio- Pronunciation: [key] a combining form meaning “sulfur,” used in chemical nomenclature in the names of compounds in which part or all of the oxygen atoms have been replaced by sulfur; often used to designate sulfur analogues of oxygen compounds. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. thin-skinned thioacetamide Related Content Daily Word Quiz: languid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language