[strato.sphere] n [F stratosphere, fr. NL stratum + -o- + F sphere sphere, fr. L sphaera] (1909) 1: the part of the earth's atmosphere which extends from about
7. miles (11 kilometers) above the surface to 31 miles (50 kilometers) and in which temperature increases gradually to about 32 degrees F (0 degrees C) and clouds rarely form
2: a very high or the highest region on or as if on a graded scale "construction costs in the ~" "the celebrity ~" -- strato.spher.ic adj