STRATOSPHERE

noun Etymology: French stratosphère, from New Latin stratum + -o- + French sphère sphere, from Latin sphaera Date: 1909 the part of the earth's atmosphere which extends from the top of the troposphere to about 30 miles (50 kilometers) above the surface and in which temperature increases gradually to about 32° F (0° C) and clouds rarely form, a very high or the highest region on or as if on a graded scale , stratospheric adjective stratospherically adverb