/ Thesaurus / U Synonyms of upton beall sinclair Find synonyms for: Noun1. Sinclair, Upton Sinclair, Upton Beall Sinclairusage: United States writer whose novels argued for social reform (1878-1968)WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: inutiae Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language