/ Dictionary / Index T thereby: Meaning and Definition of Find definitions for: there•by Pronunciation: (âr"bī', âr'bī"), [key] — adv. by that; by means of that. in that connection or relation: Thereby hangs a tale. by or near that place. about that number, quantity, or degree. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: thereby (Thesaurus) thereat therefor Related Content Daily Word Quiz: lyceum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language