/ Thesaurus / O Synonyms of oral fissure Find synonyms for: Noun1. mouth, oral cavity, oral fissure, rima oris, rimausage: the opening through which food is taken in and vocalizations emerge; "he stuffed his mouth with candy"WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: acquiesce Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language