The word "stratospheric" is built upon the noun "stratosphere," a term coined in the early 20th century for the layer of the Earth's atmosphere above the troposphere. Its first element, "strato-," derives from the Latin stratum, meaning a "spread-out" or "layered" covering, reflecting the stratified, stable nature of this atmospheric region. The second element, "-sphere," originates from the Greek concept of sphaira for a globe or celestial ball, used in scientific vocabulary to denote a spherical shell or zone. The adjective-forming suffix "-ic" was then appended, creating a term that literally means "pertaining to the layered sphere." The informal meaning of "extremely high" is a metaphorical extension from the great physical altitude of the stratosphere to describe abstract quantities like prices or levels.

Structure: strato (layer) + sphere (sphere, region) + ic (adjective suffix) - strato: From Latin stratus (past participle of sternere, meaning "to spread out, stretch, lay flat"), via scientific Latin stratum (a layer). In this word, it signifies "layer." - sphere: From Latin sphaera, from Greek sphaira (ball, globe, celestial sphere). In this word, it signifies a spherical region or zone. - ic: A suffix from Latin -icus, Greek -ikos, used to form adjectives meaning "of, pertaining to, or characteristic of."