/ Dictionary / Index W water line: Meaning and Definition of Find definitions for: wa'ter line" Pronunciation: [key] the part of the outside of a ship's hull that is just at the water level. any of a series of lines on the hull plans of a vessel representing the level to which the vessel is immersed or the bottom of the keel. Cf. the line in which water at its surface borders upon a floating body. See(def. 2). Also calleda line indicating the former level or passage of water: A water line all around the cellar served as a reminder of the flood. a pipe, hose, tube, or other line for conveying water. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: waterline (Thesaurus) water lily tulip waterlocked Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language