hf

Noun hf has 2 senses

• hf(n = noun.substance) atomic number 72, hafnium - a grey tetravalent metallic element that resembles zirconium chemically and is found in zirconium minerals; used in filaments for its ready emission of electrons;
is a kind of metal, metallic element

• hf(n = noun.attribute) high frequency - 3 to 30 megahertz;
is a kind of radio frequency
is a part of electromagnetic spectrum