/ Thesaurus / O Synonyms of oenanthe aquatica Find synonyms for: Noun1. water fennel, Oenanthe aquatica, poisonous plantusage: European poisonous herb with fibrous rootsWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: rustic Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language