1. A soft silvery-white tetravalent radioactive metallic element; isotope 232 is used as a power source in nuclear reactors; occurs in thorite and in monazite sands
   - thorium, Th

Type of: metal, metallic element

Part of: monazite, thorite

• proper fraction
• proper motion
• proper name
• proper noun
• properly
• properly speaking
• properness
• propertied
• property
• property line
• property man
• property master
• property owner
• property right
• property settlement
• property tax
• property-owning
• propertyless
• prophase
• prophecy
• prophesier
• prophesy
• prophet
• prophetess
• prophetic