1. nebulaAstronomy, etc. term
2. galaxyAstronomy, etc. term, Obsolete term, See also 銀河
Wikipedia definition
3. NebulaA nebula is an interstellar cloud of dust, hydrogen, helium and other ionized gases. Originally, nebula was a general name for any extended astronomical object, including galaxies beyond the Milky Way (some examples of the older usage survive; for example, the Andromeda Galaxy was referred to as the Andromeda Nebula before galaxies were discovered by Edwin Hubble). Nebulae are often star-forming regions, such as in the Eagle Nebula.
Read “Nebula” on English Wikipedia
Read “星雲” on Japanese Wikipedia
Read “Nebula” on DBpedia


to talk about this word.