Actinia \Ac*tin"i*a\, n.; pl. L. {Actini[ae]}, E. {Actinias}. [Latinized fr. Gr. ?, ?, ray.] (Zool.) (a) An animal of the class Anthozoa, and family {Actinid[ae]}. From a resemblance to flowers in form and color, they are often called {animal flowers} and {sea anemones}. [See {Polyp}.]. (b) A genus in the family {Actinid[ae]}. [1913 Webster]