The Collaborative International Dictionary of English v.0.48:

Alcyonaria \Al`cy*o*na"ri*a\
   (acr/l`s[i^]*[o^]*n[=a]"r[i^]*[.a]), prop. n. pl. [NL.]
   (Zool.)
   One of the orders of Anthozoa. It includes the Alcyonacea,
   Pennatulacea, and Gorgonacea.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Alcyonaria
    n 1: corals and sea anemones having eight branches [syn:
         Alcyonaria, order Alcyonaria]