/ Dictionary / Index T thir: Meaning and Definition of Find definitions for: thir Pronunciation: (ûr, ēr), [key] these. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. thioxanthene Thira Related Content Daily Word Quiz: resilient Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language