The vault of the heavens, where the clouds, sun, moon, and stars can be seen; the heavens, the sky.
In the geocentric Ptolemaic system, the eighth celestial sphere which carried the fixed stars; (countable, by extension) any celestial sphere.
The abode of God and the angels; heaven.
The field or sphere of an activity or interest.
The region of the uppermost atmosphere where temperature increases along with the altitude due to the absorption of solar ultraviolet radiation by ozone. The stratosphere extends from the tropopause (10–15 kilometers) to approximately 50 kilometers, where it is succeeded by the mesosphere.