Meaning of HF

WordNet Dictionary
	Definition:		[n]  3 to 30 megahertz [n]  a gray tetravalent metallic element that resembles zirconium chemically and is found in zirconium minerals; used in filaments for its ready emission of electrons
	Websites:
	Synonyms:		atomic number 72, hafnium, high frequency
	See Also:		electromagnetic spectrum, metal, metallic element, radio frequency