/ Thesaurus / T Synonyms of trionyx muticus Find synonyms for: Noun1. smooth softshell, Trionyx muticus, soft-shelled turtle, pancake turtleusage: river turtle of Mississippi basin; prefers running waterWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: nefarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language