/ Thesaurus / R Synonyms of river cocytus Find synonyms for: Noun1. Cocytus, River Cocytususage: (Greek mythology) a river in Hades that was said to be a tributary of the AcheronWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: aversion Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language