/ Thesaurus / F Synonyms of fish duck Find synonyms for: Noun1. merganser, fish duck, sawbill, sheldrake, sea duckusage: large crested fish-eating diving duck having a slender hooked bill with serrated edgesWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: grimace Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language