/ Dictionary / Index M merganser: Meaning and Definition of Find definitions for: mer•gan•ser Pronunciation: (mur-gan'sur), [key] — pl. -sers, -ser. any of several fish-eating diving ducks of the subfamily Merginae, having a narrow bill hooked at the tip and serrated at the edges. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: merganser (Thesaurus) meretricious merge Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language