ˈthərməˌˌ noun
Etymology: International Scientific Vocabulary therm- + sphere (I)
: the part of the earth's atmosphere that begins at about 50 miles (80 kilometers) above the earth's surface, extends to outer space, and is characterized by steadily increasing temperature with height
• ther·mo·spheric ¦ ̷ ̷ ̷ ̷ ˌ adjective