F layer flax winder • fleabane mullet · · · Info · Definitions · Synonyms · Characters · · F layer · · Text Common · · Latin · · Scripts 7 · · Length Definitions · · · (noun) the highest region of the ionosphere (from 90 to 600 miles up) which contains the highest concentration of free electrons and is most useful for long-range radio transmission. Synonyms: Appleton layer, F region. · · Noun Definition 1 Synonyms · · · degree fahrenheit · · Synonym 1 f · · Synonym 2 fluorine · · Synonym 3 atomic number 9 · · Synonym 4 farad · · Synonym 5 Characters · · space U+0020 F latin capital letter f U+0046 a latin small letter a U+0061 e latin small letter e U+0065 l latin small letter l U+006C r latin small letter r U+0072 y latin small letter y U+0079