ラグーン星せい雲うんMeanings1nounLagoon NebulaastronomyA large emission nebula in the constellation Sagittarius. The Japanese name is a direct loan translation.See also: 干潟星雲ラグーン星せい雲うんはいて座ざにある散さん光こう星せい雲うんです。The Lagoon Nebula is a diffuse nebula in the constellation Sagittarius.