WordReference Random House Unabridged Dictionary of American English © 2026
plas•ma•sphere
(plaz′mə sfēr′),USA pronunciation n. [Astron.]
- Astronomya region of cool plasma surrounding the earth, extending 8000–25,000 mi. (13,000–40,000 km) into space, and bounded by the plasmapause.
- plasma + -sphere 1965–70
'plasmasphere' also found in these entries (note: many are not synonyms or translations):