cni·dar·i·an /naɪˈdæriən, ˈdɛr-/
  cni·dar·i·an /-ɪən/ 名詞
  cnidarian
       n : radially symmetrical animals having saclike bodies with only
           one opening and tentacles with stinging structures; they
           occur in polyp and medusa forms [syn: coelenterate]