/ Thesaurus / I Synonyms of in that Find synonyms for: Adverb1. therein, in this, in thatusage: (formal) in or into that thing or place; "they can read therein what our plans are"WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language