Search Result for "f region":
Wordnet 3.0

NOUN (1)

1. 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;
[syn: Appleton layer, F layer, F region]



WordNet (r) 3.0 (2006):

F region
    n 1: 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 [syn: Appleton layer, F layer, F region]