Breadcrumb Home > Thesaurus > N Synonyms of niagara Find synonyms for: Noun 1. Niagara, Niagara Falls usage: waterfall in Canada is the Horseshoe Falls; in the United States it is the American Falls 2. Niagara, Niagara River usage: a river flowing from Lake Erie into Lake Ontario; forms boundary between Ontario and New York WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of niagara (Dictionary) TrendingHere are the facts and trivia that people are buzzing about. Jewish Holidays, 2010-2030 (A.M. 5770-5791) Western Christian Holidays, 2010-2030 12 Steps to a New Year New Year's Resolution to Slim Down? Martin Luther King Speeches Books of the Bible: Old Testament Books in Order ✖ Related Content Daily Word Quiz: voxpopuli Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language