| 1. | the region of the upper atmosphere extending upward from the tropopause to about 30 miles (50 km) above the earth, characterized by little vertical change in temperature. |
| 2. | (formerly) all of the earth's atmosphere lying outside the troposphere. |
| 3. | any great height or degree, as the highest point of a graded scale. |
The region of the atmosphere of the Earth above the troposphere. The stratosphere begins at an altitude of seven to ten miles and extends to approximately thirty miles.