/ Dictionary / Index T thereupon: Meaning and Definition of Find definitions for: there•up•on Pronunciation: (âr'u-pon", -pôn", âr"u-pon', -pôn'), [key] — adv. immediately following that. in consequence of that. upon that or it. with reference to that. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. thereunder therewith Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language