/ Thesaurus / H Synonyms of horneophyton Find synonyms for: Noun1. Horneophyton, genus Horneophyton, fern genususage: Devonian fossil plant considered one of the earliest forms of vascular land plants; similar to genus Rhynia but smallerWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: profiterole Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language