any of certain anthozoans, especially Gorgonia flabellum, of the West Indies, in which the colony assumes a fanlike form.
Origin of sea fan
First recorded in 1625–35
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for sea fan
any of various corals of the genus Gorgonia and related genera, having a treelike or fan-shaped horny skeleton: order Gorgonacea (gorgonians)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012