F REGION
    
Meaning of F REGION in English
	
Function: noun
 Date: 1923
: the highest region of the ionosphere occurring from 80 miles (130 kilometers) to more than 300 miles (500 kilometers)
	
	
	Merriam Webster Collegiate English Dictionary.
    	Merriam Webster - Энциклопедический словарь английского языка.
	2012