family Osmundaceae fa·mi·lyos·mundaceae uncommon noun 1. large family of ferns widely distributed in temperate and tropical areas SynonymsOsmundaceaefamily Osmundaceae Related words Broader terms fern family Parts Filicales Part of genus OsmundaLeptopterisTodea WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.