/ Thesaurus / E Synonyms of east river Find synonyms for: Noun1. East Riverusage: a tidal strait separating Manhattan and the Bronx from Queens and BrooklynWordNet 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