/ Thesaurus / B Synonyms of bissextile day Find synonyms for: Noun1. leap day, bissextile day, February 29, dayusage: the name of the day that is added during a leap yearWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: fabricate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language