strat ‧ os ‧ phere /ˈstrætəsfɪə $ -sfɪr/ BrE AmE noun
[ Date: 1900-2000 ; Language: French ; Origin: stratosphère , from Modern Latin stratum ( ⇨ ↑ stratum ) + French sphère 'sphere' ]
1 . the stratosphere the outer part of the air surrounding the Earth, from 10 to 50 kilometres above the Earth ⇨ atmosphere
2 . [singular] informal a very high position, level, or amount:
Oil prices soared into the stratosphere.
He’s now at the top of the political stratosphere.