/ Thesaurus / W Synonyms of water line Find synonyms for: Noun1. waterline, water line, water level, lineusage: a line corresponding to the surface of the water when the vessel is afloat on an even keel; often painted on the hull of a ship2. water line, watermark, lineusage: a line marking the level reached by a body of waterWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: magnanimous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language