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ionosphere
i·on·o·sphere [ ī ónnə sfr ]


noun 
Definition:
 
ionized layers in upper atmosphere: four layers of the Earth's upper atmosphere in which incoming ionizing radiation from space creates ions and free electrons that can reflect radio signals, enabling their transmission around the world
[Early 20th century. <ion]

i·on·o·spher·ic [ ī ònnə sfrik, ī ònnə sférrik ] adjective
i·on·o·spher·i·cal·ly adverb
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