order Alcyonaria or·de·ral·cyonaria uncommon noun 1. corals and sea anemones having eight branches SynonymsAlcyonariaorder Alcyonaria Related words Broader terms animal order Parts Anthozoa Part of AlcyonaceaPennatulidaeGorgonacea WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.