Skip to definition.
Get the FREE one-click dictionary software for Windows.
NEW iPhone Audio English dictionary


Noun: ionosphere  I'ó-nu`sfir [N. Amer], I'ó-nu`sfi-u(r) [Brit]
  1. The outer region of the Earth's atmosphere; contains a high concentration of free electrons

Derived forms: ionospheres

Type of: part, region

Part of: air, atmosphere

Encyclopedia: Ionosphere