水みず風ふう船せんみずふうせんMeanings1nounwater balloonA small balloon filled with water, often used in summer play or festivals.夏なつ祭まつりで水みず風ふう船せんを買かった。I bought a water balloon at the summer festival.子こどもたちが水みず風ふう船せんを投なげ合あって遊あそんでいる。The children are playing by throwing water balloons at each other.