The Collaborative International Dictionary of English v.0.48:

Actinaria \Ac`ti*na"ri*a\, n. pl. [NL., from Gr. ?, ?, ray.]
   (Zool.)
   An order of Anthozoa, including those which have simple
   tentacles and do not form stony corals. Sometimes, in a wider
   sense, applied to all the Anthozoa, expert the Alcyonaria,
   whether forming corals or not.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Anthozoa \An`tho*zo"a\, n. pl. [NL., fr. Gr. 'a`nqos flower + ?
   animal.] (Zool.)
   The class of the C[oe]lenterata which includes the corals and
   sea anemones. The three principal groups or orders are
   Acyonaria, Actinaria, and Madreporaria.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Actinaria
    n 1: sea anemones [syn: Actiniaria, order Actiniaria,
         Actinaria, order Actinaria]