/ Thesaurus / E Synonyms of euphrates river Find synonyms for: Noun1. Euphrates, Euphrates Riverusage: a river in southwestern Asia; flows into the Persian Gulf; was important in the development of several great civilizations in ancient MesopotamiaWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: labyrinth Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language