Definitions:

1. A chemical agent with the symbol Hf and atomic number 72. NOUN
   • Hafnium's ability to absorb neutrons makes it essential for controlling nuclear reactions in power plants.
2. A lustrous, silver-gray transition metal that is chemically similar to zirconium and is often found in zirconium minerals. NOUN
   • The aerospace industry uses hafnium in superalloys due to its ability to withstand extreme temperatures.
3. Type of metal that is corrosion-resistant and has high neutron-absorption properties, making it useful in nuclear reactors as control rods. NOUN
   • The reactor's control rods are made from hafnium to effectively absorb neutrons during the fission process.

Synonyms:

• base metal
• hf