/ Dictionary / Index T thereinafter: Meaning and Definition of Find definitions for: there•in•af•ter Pronunciation: (âr"in-af'tur, -äf'-), [key] — adv. afterward in that document. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: thereinafter (Thesaurus) therein thereinto Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language