/ Dictionary / Index T TBI: Meaning and Definition of Find definitions for: TBI Pronunciation: [key] — Auto. Auto. See Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. TBD Tbilisi Related Content Daily Word Quiz: pugilist Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language