/ Dictionary / Index T thyroid: Meaning and Definition of Find definitions for: thy•roid Pronunciation: (thī'roid), [key] — adj. of or pertaining to the thyroid gland. of or pertaining to the largest cartilage of the larynx, forming the projection known in humans as the Adam's apple. —n. See the thyroid cartilage. See diag. under an artery, vein, etc., in the thyroid region. a preparation made from the thyroid glands of certain animals, used in treating hypothyroid conditions. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: thyroid (Thesaurus) thyro- thyroidectomy 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