1. (noun)Portuguese man-of-war, man-of-war, jellyfish large siphonophore having a bladderlike float and stinging tentacles Synonyms: ship of the line, man-of-war, jellyfish
2. (noun)jellyfish any of numerous usually marine and free-swimming coelenterates that constitute the sexually reproductive forms of hydrozoans and scyphozoans Synonyms: man-of-war