noun
: any of the numerous luminous or dark formations or irregularly distributed dust and gas seen within the Milky Way galaxy and in other spiral galaxies but not including the planetary nebulae
noun
: any of the numerous luminous or dark formations or irregularly distributed dust and gas seen within the Milky Way galaxy and in other spiral galaxies but not including the planetary nebulae
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012