/ Thesaurus / T Synonyms of thornless Find synonyms for: Adjective1. thornless, spineless, unarmed (vs. armed)usage: lacking thornsWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: ravenous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language