ionosphere

Từ điển Oxford Learners Wordfinder Dictionary

noun

the outer region of the Earth's atmosphere;
contains a high concentration of free electrons
• Hypernyms:
region, part
• Part Holonyms:
atmosphere, air
• Part Meronyms:
D-layer, D region, Appleton layer, F layer, F region,
Heaviside layer, Kennelly-Heaviside layer, E layer, E region