/ Dictionary / Index T thyro-: Meaning and Definition of Find definitions for: thyro- Pronunciation: [key] a combining form representingin the formation of compound words: thyrotropin. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. thyristor thyroid Related Content Daily Word Quiz: immense Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language