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A colonial siphonophore (Physalia physalis) composed of numerous specialized zooids, having a bluish bladderlike crested float from which hang numerous long stinging tentacles.
(Animals) any of several large complex colonial hydrozoans of the genus Physalia, esp P. physalis, having an aerial float and long stinging tentacles: order Siphonophora. Sometimes shortened to: man-of-war
any of several large, colonial marine hydrozoans of the genus Physalia, having a buoyant saillike sac from which dangle poisonous stinging tentacles.