/ Dictionary / Index T thā: Meaning and Definition of Find definitions for: thā Pronunciation: (thä), [key] — n. the fourth letter of the Arabic alphabet. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Th Thach Related Content Daily Word Quiz: tenacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language