/ Dictionary / Index T thallic: Meaning and Definition of Find definitions for: thal•lic Pronunciation: (thal'ik), [key] — adj. Chem. of or containing thallium, esp. in the trivalent state. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. thalidomide thallium Related Content Daily Word Quiz: impetuous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language