/ Dictionary / Index T thyrotoxic: Meaning and Definition of Find definitions for: thy•ro•tox•ic Pronunciation: (thī"rō-tok'sik), [key] — adj. Pathol. of or pertaining to a condition caused by excessive thyroid hormone in the system, usually resulting from overactivity of the thyroid gland. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: thyrotoxic (Thesaurus) thyrotomy thyrotoxicosis Related Content Daily Word Quiz: philtrum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language