/ Thesaurus / M Synonyms of merrimack river Find synonyms for: Noun1. Merrimack, Merrimack Riverusage: a river that rises in south central New Hampshire and flows through Concord and Manchester into Massachusetts and empties into the Atlantic OceanWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: candid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language