/ Thesaurus / F Synonyms of free thought Find synonyms for: Noun1. deism, free thought, rationalismusage: the form of theological rationalism that believes in God on the basis of reason without reference to revelationWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: dormant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language