/ Thesaurus / S Synonyms of spiral galaxy Find synonyms for: Noun1. spiral galaxy, spiral nebula, galaxy, extragalactic nebulausage: a galaxy having a spiral structure; arms containing younger stars spiral out from old stars at the centerWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: loathe Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language