gorgonian
noun
gor·go·ni·an gȯr-ˈgō-nē-ən 
: any of an order (Gorgonacea) of colonial often colorful anthozoan corals that have a stiff branching skeleton and include the sea whips and sea fans
gorgonian adjective
Example Sentences
Recent Examples on the Web Looking at the patterns of sessile, or immobile, species like corals, macroalgae, sponges, and gorgonians—a type of coral that includes sea fans—the team found that animals living in deeper waters were likely to have longer lives. 
National Geographic, 31 Mar. 2018
National Geographic, 31 Mar. 2018 Word History
Etymology
New Latin Gorgonia, a coral genus, from Latin, coral, from Gorgon-, Gorgo
First Known Use
1835, in the meaning defined above