/ Thesaurus / A Synonyms of autumnal equinox Find synonyms for: Noun1. autumnal equinox, September equinox, fall equinox, equinoxusage: September 222. autumnal equinox, equinoctial point, equinoxusage: (astronomy) the equinoctial point that lies in the constellation of VirgoWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: torrid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language