ionosphere Ionornis • ionospheric · · · Info · Definitions · Characters · · ionosphere · · Text Latin · · Script 10 · · Length Definitions · · · (noun) the outer region of the Earth's atmosphere; contains a high concentration of free electrons. · · Noun Definition 1 Characters · · e latin small letter e U+0065 h latin small letter h U+0068 i latin small letter i U+0069 n latin small letter n U+006E o latin small letter o U+006F p latin small letter p U+0070 r latin small letter r U+0072 s latin small letter s U+0073