/ Thesaurus / B Synonyms of basic assumption Find synonyms for: Noun1. basic assumption, constatation, self-evident truth, assumption, supposition, supposalusage: an assumption that is basic to an argumentWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: industrious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language